// CalendricalCalculations.cs
//
// (C) Ulrich Kunitz 2002
//
//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
namespace System.Globalization{
using System.Collections;
/// <summary>A class that provides mathematical functions.</summary>
/// <remarks>
/// <para>
/// We are breaking the .Net
/// naming conventions to be compatible to the "Calendrical Calculations"
/// bool.
/// </para>
/// </remarks>
internal class CCMath {
/// <summary>
/// A static method which rounds a double value.
/// </summary>
/// <param name="x">The double value to round.</param>
/// <returns>The rounded double.</returns>
public static double round(double x) {
return System.Math.Floor(x+0.5);
}
/// <summary>
/// A static method that computes the remainder of the division
/// of two doubles.
/// </summary>
/// <param name="x">The double value which is divided.</param>
/// <param name="y">The divisor.</param>
/// <returns>The remainder as double value.</returns>
public static double mod(double x, double y) {
return x - y * System.Math.Floor(x/y);
}
/// <summary>
/// The static method divides two integers.
/// </summary>
/// <param name="x">The integer x value.</param>
/// <param name="y">The integer y value.</param>
/// <returns>The qotient of x and y defined by floor(x/y).
/// </returns>
/// <remarks>
/// Please notify that the function is not compatible to the standard
/// integer divide operation /.
/// </remarks>
public static int div(int x, int y) {
return (int)System.Math.Floor((double)x/(double)y);
}
/// <summary>
/// The static method computes the remainder of two integers.
/// </summary>
/// <param name="x">The integer value which will be divided.</param>
/// <param name="y">The divisor integer value.</param>
/// <returns> The remainder as integer value.</returns>
/// <remarks>
/// Please notify that the method is not compatible to the C#
/// remainder operation %.
/// </remarks>
public static int mod(int x, int y) {
return x - y * div(x, y);
}
/// <summary>
/// A static method that combines integer division and remainder
/// computation.
/// </summary>
/// <param name="remainder">Remainder integer output value.
/// </param>
/// <param name="x">Integer to be divided.</param>
/// <param name="y">Divisor integer value.</param>
/// <returns>The quotient as integer.</returns>
/// <seealso cref="M:div"/>
/// <seealso cref="M:mod"/>
public static int div_mod(out int remainder, int x, int y) {
int d = div(x, y);
remainder = x - y * d;
return d;
}
/// <summary>
/// A static method returning the sign of the argument.
/// </summary>
/// <param name="x">The double argument.</param>
/// <returns>An integer value: -1 for a negative argument;
/// 0 for a zero argument, and 1 for a positive argument.
/// </returns>
public static int signum(double x) {
if (x < 0.0)
return -1;
if (x == 0.0)
return 0;
return 1;
}
/// <summary>
/// A static method returning the sign of the integer
/// argument.
/// </summary>
/// <param name="x">The integer argument.</param>
/// <returns>An integer value: -1 for a negative argument;
/// 0 for a zero argument, and 1 for a positive argument.
/// </returns>
public static int signum(int x) {
if (x < 0)
return -1;
if (x == 0)
return 0;
return 1;
}
/// <summary>
/// An adjusted remainder function as defined in "Calendrical
/// Calculations".
/// </summary>
/// <param name="x">The double x argument.</param>
/// <param name="y">The double y argument, the divisor.</param>
/// <returns>A double value representing remainder; but instead 0.0
/// the divisor y is returned.
/// </returns>
public static double amod(double x, double y) {
double d = mod(x, y);
return (d == 0.0) ? y : d;
}
/// <summary>
/// The adjusted remainder functions for integers as defined in
/// "Calendrical Calculations".
/// </summary>
/// <param name="x">The integer argument to be divided.</param>
/// <param name="y">The integer divisor argument.</param>
/// <returns>The remainder as an integer; however instead 0
/// is the divisor y returned.
/// </returns>
public static int amod(int x, int y) {
int i = mod(x, y);
return (i == 0) ? y : i;
}
}
/// <summary>The class implements methods to handle the fixed date value from
/// the "Calendrical Calculations" books.
/// </summary>
/// <remarks>
/// <para>
/// For implementing the Calendar classes I used the algorithms from the
/// book "Calendrical Calculations" by Nachum Dershowitz and Edward M.
/// Rheingold, second reprint 1998. Trying to prevent the introduction of new
/// bugs, I implemented their algorithms in the
/// <see cref="N:CalendricalCalculations"/>
/// namespace and wrapped it in the calendar classes.
/// </para>
/// <para>
/// The fixed day number is also known as R.D. - rata die.
/// Midnight at the onset of Monday,
/// January 1, year 1 (Gregorian) is R.D. 1.
/// </para>
/// <para>Here are all my references:</para>
/// <list type="table">
/// <item><description>
/// [1] Nachum Dershowitz and Edward M. Rheingold: "Calendrical Calculations";
/// Cambridge University Press; second reprint 1998.
/// </description></item>
/// <item><description>
/// [2] P. Kenneth Seidelmann (ed.): "Explanatory Supplement to the Astronomical
/// Almanac"; University Science Books, Sausalito; 1992
/// </description></item>
/// <item><description>
/// [3] F. Richard Stephenson: "Historical Eclipses and Earth Rotation";
/// Cambridge University Press; 1997
/// </description></item>
/// </list>
/// </remarks>
internal class CCFixed {
/// <summary>The method computes the
/// <see cref="T:System.DateTime"/>
/// from a fixed day number.
/// </summary>
/// <param name="date">A integer representing the fixed day number.
/// </param>
/// <returns>The <see cref="T:System.DateTime"/> representing
/// the date.
/// </returns>
public static System.DateTime ToDateTime(int date) {
long ticks = (date - 1) * System.TimeSpan.TicksPerDay;
return new System.DateTime(ticks);
}
/// <summary>The method computes the
/// <see cref="T:System.DateTime"/>
/// from a fixed day number and time arguments.
/// </summary>
/// <param name="date">An integer representing the fixed day number.
/// </param>
/// <param name="hour">An integer argument specifying the hour.
/// </param>
/// <param name="minute">An integer argument specifying the minute.
/// </param>
/// <param name="second">An integer argument giving the second.
/// </param>
/// <param name="milliseconds">An double argument specifying
/// the milliseconds. Notice that
/// <see cref="T:System.DateTime"/> has 100 nanosecond resolution.
/// </param>
/// <returns>The <see cref="T:System.DateTime"/> representing
/// the date.
/// </returns>
public static System.DateTime ToDateTime(int date,
int hour, int minute, int second, double milliseconds)
{
System.DateTime time = ToDateTime(date);
time = time.AddHours(hour);
time = time.AddMinutes(minute);
time = time.AddSeconds(second);
return time.AddMilliseconds(milliseconds);
}
/// <summary>
/// A static method computing the fixed day number from a
/// <see cref="T:System.DateTime"/> value.
/// </summary>
/// <param name="time">A
/// <see cref="T:System.DateTime"/> value representing the date.
/// </param>
/// <returns>The fixed day number as integer representing the date.
/// </returns>
public static int FromDateTime(System.DateTime time) {
return 1 + (int)(time.Ticks / System.TimeSpan.TicksPerDay);
}
/// <summary>
/// The static method computes the <see cref="T:DayOfWeek"/>.
/// </summary>
/// <param name="date">An integer representing the fixed day number.
/// </param>
/// <returns>The day of week.</returns>
public static DayOfWeek day_of_week(int date) {
return (DayOfWeek)CCMath.mod(date, 7);
}
/// <summary>
/// The static method computes the date of a day of week on or before
/// a particular date.
/// </summary>
/// <param name="date">An integer representing the date as
/// fixed day number.
/// </param>
/// <param name="k">An integer representing the day of the week,
/// starting with 0 for sunday.
/// </param>
/// <returns>The fixed day number of the day of week specified by k
/// on or before the given date.
/// </returns>
public static int kday_on_or_before(int date, int k) {
return date - (int)day_of_week(date-k);
}
/// <summary>
/// The static method computes the date of a day of week on or after
/// a particular date.
/// </summary>
/// <param name="date">An integer representing the date as
/// fixed day number.
/// </param>
/// <param name="k">An integer representing the day of the week,
/// starting with 0 for sunday.
/// </param>
/// <returns>The fixed day number of the day of week specified by k
/// on or after the given date.
/// </returns>
public static int kday_on_or_after(int date, int k) {
return kday_on_or_before(date+6, k);
}
/// <summary>
/// The static method computes the date of a day of week that is
/// nearest to a particular date.
/// </summary>
/// <param name="date">An integer representing the date as
/// fixed day number.
/// </param>
/// <param name="k">An integer representing the day of the week,
/// starting with 0 for sunday.
/// </param>
/// <returns>The fixed day number of the day of week neares to the
/// given date.
/// </returns>
public static int kd_nearest(int date, int k) {
return kday_on_or_before(date+3, k);
}
/// <summary>
/// The static method computes the date of a day of week after
/// a particular date.
/// </summary>
/// <param name="date">An integer representing the date as
/// fixed day number.
/// </param>
/// <param name="k">An integer representing the day of the week,
/// starting with 0 for sunday.
/// </param>
/// <returns>The fixed day number of the day of week specified by k
/// after the given date.
/// </returns>
public static int kday_after(int date, int k) {
return kday_on_or_before(date+7, k);
}
/// <summary>
/// The static method computes the date of a day of week before
/// a particular date.
/// </summary>
/// <param name="date">An integer representing the date as
/// fixed day number.
/// </param>
/// <param name="k">An integer representing the day of the week,
/// starting with 0 for sunday.
/// </param>
/// <returns>The fixed day number of the day of week specified by k
/// before the given date.
/// </returns>
public static int kday_before(int date, int k) {
return kday_on_or_before(date-1, k);
}
} // class CCFixed
/// <summary>
/// A class encapsulating the functions of the Gregorian calendar as static
/// methods.
/// </summary>
/// <remarks>
/// <para>
/// This class is not compatible to
/// <see cref="T:System.Globalization.GregorianCalendar"/>.
/// </para>
/// <para>
/// The fixed day number is also known as R.D. - rata die.
/// Midnight at the onset of Monday,
/// January 1, year 1 (Gregorian) is R.D. 1.
/// </para>
/// <seealso cref="T:CCFixed"/>
/// </remarks>
internal class CCGregorianCalendar {
/// <summary>An integer defining the epoch of the Gregorian calendar
/// as fixed day number.</summary>
/// <remarks>The epoch is January 3, 1 C.E. (Julian).</remarks>
const int epoch = 1;
/// <summary>The enumeration defines the months of the Gregorian
/// calendar.
/// </summary>
public enum Month {
/// <summary>
/// January.
/// </summary>
january = 1,
/// <summary>
/// February.
/// </summary>
february,
/// <summary>
/// March.
/// </summary>
march,
/// <summary>
/// April.
/// </summary>
april,
/// <summary>
/// May.
/// </summary>
may,
/// <summary>
/// June.
/// </summary>
june,
/// <summary>
/// July.
/// </summary>
july,
/// <summary>
/// August.
/// </summary>
august,
/// <summary>
/// September.
/// </summary>
september,
/// <summary>
/// October.
/// </summary>
october,
/// <summary>
/// November.
/// </summary>
november,
/// <summary>
/// December.
/// </summary>
december
};
/// <summary>
/// The method tells whether the year is a leap year.
/// </summary>
/// <param name="year">An integer representing the Gregorian year.
/// </param>
/// <returns>A boolean which is true if <paramref name="year"/> is
/// a leap year.
/// </returns>
public static bool is_leap_year(int year) {
if (CCMath.mod(year, 4) != 0)
return false;
switch (CCMath.mod(year, 400)) {
case 100:
return false;
case 200:
return false;
case 300:
return false;
}
return true;
}
/// <summary>
/// The method returns the fixed day number of the given Gregorian
/// date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Gregorian year.
/// </param>
/// <param name="year">An integer representing the Gregorian year.
/// Non-positive values are allowed also.
/// </param>
/// <returns>An integer value representing the fixed day number.
/// </returns>
public static int fixed_from_dmy(int day, int month, int year) {
int k = epoch - 1;
k += 365 * (year-1);
k += CCMath.div(year-1, 4);
k -= CCMath.div(year-1, 100);
k += CCMath.div(year-1, 400);
k += CCMath.div(367*month-362, 12);
if (month > 2) {
k += is_leap_year(year) ? -1 : -2;
}
k += day;
return k;
}
/// <summary>
/// The method computes the Gregorian year from a fixed day number.
/// </summary>
/// <param name="date">The fixed day number.
/// </param>
/// <returns>An integer value giving the Gregorian year of the date.
/// </returns>
public static int year_from_fixed(int date) {
int d = date - epoch;
int n_400 = CCMath.div_mod(out d, d, 146097);
int n_100 = CCMath.div_mod(out d, d, 36524);
int n_4 = CCMath.div_mod(out d, d, 1461);
int n_1 = CCMath.div(d, 365);
int year = 400*n_400 + 100*n_100 + 4*n_4 + n_1;
return (n_100 == 4 || n_1 == 4) ? year : year + 1;
}
/// <summary>
/// The method computes the Gregorian year and month from a fixed day
/// number.
/// </summary>
/// <param name="month">The output value giving the Gregorian month.
/// </param>
/// <param name="year">The output value giving the Gregorian year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void my_from_fixed(out int month, out int year,
int date)
{
year = year_from_fixed(date);
int prior_days = date - fixed_from_dmy(1, (int)Month.january,
year);
int correction;
if (date < fixed_from_dmy(1, (int)Month.march, year)) {
correction = 0;
} else if (is_leap_year(year)) {
correction = 1;
} else {
correction = 2;
}
month = CCMath.div(12 * (prior_days + correction) + 373, 367);
}
/// <summary>
/// The method computes the Gregorian year, month, and day from a
/// fixed day number.
/// </summary>
/// <param name="day">The output value returning the day of the
/// month.
/// </param>
/// <param name="month">The output value giving the Gregorian month.
/// </param>
/// <param name="year">The output value giving the Gregorian year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void dmy_from_fixed(out int day, out int month,
out int year,
int date)
{
my_from_fixed(out month, out year, date);
day = date - fixed_from_dmy(1, month, year) + 1;
}
/// <summary>A method computing the Gregorian month from a fixed
/// day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the Gregorian month.
/// </returns>
public static int month_from_fixed(int date) {
int month, year;
my_from_fixed(out month, out year, date);
return month;
}
/// <summary>
/// A method computing the day of the month from a fixed day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the day of the month.
/// </returns>
public static int day_from_fixed(int date) {
int day, month, year;
dmy_from_fixed(out day, out month, out year, date);
return day;
}
/// <summary>
/// The method computes the difference between two Gregorian dates.
/// </summary>
/// <param name="dayA">The integer parameter gives the day of month
/// of the first date.
/// </param>
/// <param name="monthA">The integer parameter gives the Gregorian
/// month of the first date.
/// </param>
/// <param name="yearA">The integer parameter gives the Gregorian
/// year of the first date.
/// </param>
/// <param name="dayB">The integer parameter gives the day of month
/// of the second date.
/// </param>
/// <param name="monthB">The integer parameter gives the Gregorian
/// month of the second date.
/// </param>
/// <param name="yearB">The integer parameter gives the Gregorian
/// year of the second date.
/// </param>
/// <returns>An integer giving the difference of days from the first
/// the second date.
/// </returns>
public static int date_difference(int dayA, int monthA, int yearA,
int dayB, int monthB, int yearB)
{
return fixed_from_dmy(dayB, monthB, yearB) -
fixed_from_dmy(dayA, monthA, yearA);
}
/// <summary>
/// The method computes the number of the day in the year from
/// a Gregorian date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Gregorian year.
/// </param>
/// <param name="year">An integer representing the Gregorian year.
/// Non-positive values are allowed also.
/// </param>
/// <returns>An integer value giving the number of the day in the
/// Gregorian year, counting from 1.
/// </returns>
public static int day_number(int day, int month, int year) {
return date_difference(31, (int)Month.december, year-1,
day, month, year);
}
/// <summary>
/// The method computes the days remaining in the given Gregorian
/// year from a Gregorian date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Gregorian year.
/// </param>
/// <param name="year">An integer representing the Gregorian year.
/// Non-positive values are allowed also.
/// </param>
/// <returns>An integer value giving the number of days remaining in
/// the Gregorian year.
/// </returns>
public static int days_remaining(int day, int month, int year) {
return date_difference(day, month, year,
31, (int)Month.december, year);
}
// Helper functions for the Gregorian calendars.
/// <summary>
/// Adds months to the given date.
/// </summary>
/// <param name="time">The
/// <see cref="T:System.DateTime"/> to which to add
/// months.
/// </param>
/// <param name="months">The number of months to add.</param>
/// <returns>A new <see cref="T:System.DateTime"/> value, that
/// results from adding <paramref name="months"/> to the specified
/// DateTime.</returns>
public static System.DateTime AddMonths(System.DateTime time,
int months)
{
int rd = CCFixed.FromDateTime(time);
int day, month, year;
dmy_from_fixed(out day, out month, out year, rd);
month += months;
year += CCMath.div_mod(out month, month, 12);
int maxday = GetDaysInMonth (year, month);
if (day > maxday)
day = maxday;
rd = fixed_from_dmy(day, month, year);
System.DateTime t = CCFixed.ToDateTime(rd);
return t.Add(time.TimeOfDay);
}
/// <summary>
/// Adds years to the given date.
/// </summary>
/// <param name="time">The
/// <see cref="T:System.DateTime"/> to which to add
/// months.
/// </param>
/// <param name="years">The number of years to add.</param>
/// <returns>A new <see cref="T:System.DateTime"/> value, that
/// results from adding <paramref name="years"/> to the specified
/// DateTime.</returns>
public static System.DateTime AddYears(System.DateTime time,
int years)
{
int rd = CCFixed.FromDateTime(time);
int day, month, year;
dmy_from_fixed(out day, out month, out year, rd);
year += years;
int maxday = GetDaysInMonth (year, month);
if (day > maxday)
day = maxday;
rd = fixed_from_dmy(day, month, year);
System.DateTime t = CCFixed.ToDateTime(rd);
return t.Add(time.TimeOfDay);
}
/// <summary>
/// Gets the of the month from <paramref name="time"/>.
/// </summary>
/// <param name="time">The
/// <see cref="T:System.DateTime"/> that specifies a
/// date.
/// </param>
/// <returns>An integer giving the day of months, starting with 1.
/// </returns>
public static int GetDayOfMonth(System.DateTime time) {
return day_from_fixed(CCFixed.FromDateTime(time));
}
/// <summary>
/// The method gives the number of the day in the year.
/// </summary>
/// <param name="time">The
/// <see cref="T:System.DateTime"/> that specifies a
/// date.
/// </param>
/// <returns>An integer representing the day of the year,
/// starting with 1.</returns>
public static int GetDayOfYear(System.DateTime time) {
int rd = CCFixed.FromDateTime(time);
int year = year_from_fixed(rd);
int rd1_1 = fixed_from_dmy(1, 1, year);
return rd - rd1_1 + 1;
}
/// <summary>
/// A method that gives the number of days of the specified
/// month of the <paramref name="year"/>.
/// </summary>
/// <param name="year">An integer that gives the year in the current
/// era.</param>
/// <param name="month">An integer that gives the month, starting
/// with 1.</param>
/// <returns>An integer that gives the number of days of the
/// specified month.</returns>
public static int GetDaysInMonth(int year, int month) {
int rd1 = fixed_from_dmy(1, month, year);
int rd2 = fixed_from_dmy(1, month+1, year);
return rd2 - rd1;
}
/// <summary>
/// The method gives the number of days in the specified year.
/// </summary>
/// <param name="year">An integer that gives the year.
/// </param>
/// <returns>An integer that gives the number of days of the
/// specified year.</returns>
public static int GetDaysInYear(int year) {
int rd1 = fixed_from_dmy(1, 1, year);
int rd2 = fixed_from_dmy(1, 1, year+1);
return rd2 - rd1;
}
/// <summary>
/// The method gives the number of the month of the specified
/// date.
/// </summary>
/// <param name="time">The
/// <see cref="T:System.DateTime"/> that specifies a
/// date.
/// </param>
/// <returns>An integer representing the month,
/// starting with 1.</returns>
public static int GetMonth(System.DateTime time) {
return month_from_fixed(CCFixed.FromDateTime(time));
}
/// <summary>
/// The method gives the number of the year of the specified
/// date.
/// </summary>
/// <param name="time">The
/// <see cref="T:System.DateTime"/> that specifies a
/// date.
/// </param>
/// <returns>An integer representing the year.
/// </returns>
public static int GetYear(System.DateTime time) {
return year_from_fixed(CCFixed.FromDateTime(time));
}
/// <summary>
/// A virtual method that tells whether the given day
/// is a leap day.
/// </summary>
/// <param name="year">An integer that specifies the year.
/// </param>
/// <param name="month">An integer that specifies the month.
/// </param>
/// <param name="day">An integer that specifies the day.
/// </param>
/// <returns>A boolean that tells whether the given day is a leap
/// day.
/// </returns>
public static bool IsLeapDay(int year, int month, int day) {
return is_leap_year(year) && month == 2 && day == 29;
}
/// <summary>
/// A method that creates the
/// <see cref="T:System.DateTime"/> from the parameters.
/// </summary>
/// <param name="year">An integer that gives the year
/// </param>
/// <param name="month">An integer that specifies the month.
/// </param>
/// <param name="day">An integer that specifies the day.
/// </param>
/// <param name="hour">An integer that specifies the hour.
/// </param>
/// <param name="minute">An integer that specifies the minute.
/// </param>
/// <param name="second">An integer that gives the second.
/// </param>
/// <param name="milliseconds">An integer that gives the
/// milliseconds.
/// </param>
/// <returns>A
/// <see cref="T:system.DateTime"/> representig the date and time.
/// </returns>
public static System.DateTime ToDateTime(int year, int month, int day,
int hour, int minute, int second, int milliseconds)
{
return CCFixed.ToDateTime(fixed_from_dmy(day, month, year),
hour, minute, second, milliseconds);
}
} // class CCGregorianCalendar
/// <summary>
/// A class encapsulating the functions of the Julian calendar as static
/// methods.
/// </summary>
/// <remarks>
/// <para>The algorithms don't support a year 0. Years before Common Era
/// (B.C.E. or B.C.) are negative and years of Common Era (C.E. or A.D.)
/// are positive.
/// </para>
/// <para>
/// This class is not compatible to
/// <see cref="T:System.Globalization.JulianCalendar"/>.
/// </para>
/// <seealso cref="T:CCFixed"/>
/// </remarks>
internal class CCJulianCalendar {
/// <summary>An integer defining the epoch of the Julian calendar
/// as fixed day number.</summary>
/// <remarks>The epoch is December 30, 0 (Gregorian).</remarks>
const int epoch = -1; // 30. 12. 0 Gregorian
/// <summary>The enumeration defines the months of the Julian
/// calendar.
/// </summary>
public enum Month {
/// <summary>
/// January.
/// </summary>
january = 1,
/// <summary>
/// February.
/// </summary>
february,
/// <summary>
/// March.
/// </summary>
march,
/// <summary>
/// April.
/// </summary>
april,
/// <summary>
/// May.
/// </summary>
may,
/// <summary>
/// June.
/// </summary>
june,
/// <summary>
/// July.
/// </summary>
july,
/// <summary>
/// August.
/// </summary>
august,
/// <summary>
/// September.
/// </summary>
september,
/// <summary>
/// October.
/// </summary>
october,
/// <summary>
/// November.
/// </summary>
november,
/// <summary>
/// December.
/// </summary>
december
};
/// <summary>
/// The method tells whether the year is a leap year.
/// </summary>
/// <param name="year">An integer representing the Julian year.
/// </param>
/// <returns>A boolean which is true if <paramref name="year"/> is
/// a leap year.
/// </returns>
public static bool is_leap_year(int year) {
return CCMath.mod(year, 4) == (year > 0 ? 0 : 3);
}
/// <summary>
/// The method returns the fixed day number of the given Julian
/// date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Julian year.
/// </param>
/// <param name="year">An integer representing the Julian year.
/// Positive and Negative values are allowed.
/// </param>
/// <returns>An integer value representing the fixed day number.
/// </returns>
public static int fixed_from_dmy(int day, int month, int year) {
int y = year < 0 ? year+1 : year;
int k = epoch - 1;
k += 365 * (y-1);
k += CCMath.div(y-1, 4);
k += CCMath.div(367*month-362, 12);
if (month > 2) {
k += is_leap_year(year) ? -1 : -2;
}
k += day;
return k;
}
/// <summary>
/// The method computes the Julian year from a fixed day number.
/// </summary>
/// <param name="date">The fixed day number.
/// </param>
/// <returns>An integer value giving the Julian year of the date.
/// </returns>
public static int year_from_fixed(int date) {
int approx = CCMath.div(4*(date-epoch)+1464, 1461);
return approx <= 0 ? approx - 1 : approx;
}
/// <summary>
/// The method computes the Julian year and month from a fixed day
/// number.
/// </summary>
/// <param name="month">The output value giving the Julian month.
/// </param>
/// <param name="year">The output value giving the Julian year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void my_from_fixed(out int month, out int year, int date)
{
year = year_from_fixed(date);
int prior_days = date - fixed_from_dmy(1, (int)Month.january,
year);
int correction;
if (date < fixed_from_dmy(1, (int)Month.march, year)) {
correction = 0;
} else if (is_leap_year(year)) {
correction = 1;
} else {
correction = 2;
}
month = CCMath.div(12 * (prior_days + correction) + 373, 367);
}
/// <summary>
/// The method computes the Julian year, month, and day from a
/// fixed day number.
/// </summary>
/// <param name="day">The output value returning the day of the
/// month.
/// </param>
/// <param name="month">The output value giving the Julian month.
/// </param>
/// <param name="year">The output value giving the Julian year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void dmy_from_fixed(out int day, out int month,
out int year, int date)
{
my_from_fixed(out month, out year, date);
day = date - fixed_from_dmy(1, month, year) + 1;
}
/// <summary>A method computing the Julian month from a fixed
/// day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the Julian month.
/// </returns>
public static int month_from_fixed(int date) {
int month, year;
my_from_fixed(out month, out year, date);
return month;
}
/// <summary>
/// A method computing the day of the month from a fixed day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the day of the month.
/// </returns>
public static int day_from_fixed(int date) {
int day;
int month;
int year;
dmy_from_fixed(out day, out month, out year, date);
return day;
}
/// <summary>
/// The method computes the difference between two Julian dates.
/// </summary>
/// <param name="dayA">The integer parameter gives the day of month
/// of the first date.
/// </param>
/// <param name="monthA">The integer parameter gives the Julian
/// month of the first date.
/// </param>
/// <param name="yearA">The integer parameter gives the Julian
/// year of the first date.
/// </param>
/// <param name="dayB">The integer parameter gives the day of month
/// of the second date.
/// </param>
/// <param name="monthB">The integer parameter gives the Julian
/// month of the second date.
/// </param>
/// <param name="yearB">The integer parameter gives the Julian
/// year of the second date.
/// </param>
/// <returns>An integer giving the difference of days from the first
/// the second date.
/// </returns>
public static int date_difference(int dayA, int monthA, int yearA,
int dayB, int monthB, int yearB)
{
return fixed_from_dmy(dayB, monthB, yearB) -
fixed_from_dmy(dayA, monthA, yearA);
}
/// <summary>
/// The method computes the number of the day in the year from
/// a Julian date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Julian year.
/// </param>
/// <param name="year">An integer representing the Julian year.
/// Negative values are allowed also.
/// </param>
/// <returns>An integer value giving the number of the day in the
/// Julian year, counting from 1.
/// </returns>
public static int day_number(int day, int month, int year) {
return date_difference(31, (int)Month.december, year-1,
day, month, year);
}
/// <summary>
/// The method computes the days remaining in the given Julian
/// year from a Julian date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Julian year.
/// </param>
/// <param name="year">An integer representing the Julian year.
/// Negative values are allowed also.
/// </param>
/// <returns>An integer value giving the number of days remaining in
/// the Julian year.
/// </returns>
public static int days_remaining(int day, int month, int year) {
return date_difference(day, month, year,
31, (int)Month.december, year);
}
} // class CCJulianCalendar
/// <summary>
/// A class encapsulating the functions of the Hebrew calendar as static
/// methods.
/// </summary>
/// <remarks>
/// <para>
/// This class is not compatible to
/// <see cref="T:System.Globalization.HebrewCalendar"/>.
/// </para>
/// <seealso cref="T:CCFixed"/>
/// </remarks>
internal class CCHebrewCalendar {
/// <summary>An integer defining the epoch of the Hebrew calendar
/// as fixed day number.</summary>
/// <remarks>The epoch is October 10, 3761 B.C.E. (Julian).</remarks>
const int epoch = -1373427;
/// <summary>The enumeration defines the months of the Gregorian
/// calendar.
/// </summary>
/// <remarks>
/// The enumaration differs from .NET which defines Tishri as month 1.
/// </remarks>
public enum Month {
/// <summary>
/// Nisan.
/// </summary>
nisan = 1,
/// <summary>
/// Iyyar.
/// </summary>
iyyar,
/// <summary>
/// Sivan.
/// </summary>
sivan,
/// <summary>
/// Tammuz.
/// </summary>
tammuz,
/// <summary>
/// Av.
/// </summary>
av,
/// <summary>
/// Elul.
/// </summary>
elul,
/// <summary>
/// Tishri.
/// </summary>
tishri,
/// <summary>
/// Heshvan.
/// </summary>
heshvan,
/// <summary>
/// Kislev.
/// </summary>
kislev,
/// <summary>
/// Teveth.
/// </summary>
teveth,
/// <summary>
/// Shevat.
/// </summary>
shevat,
/// <summary>
/// Adar.
/// </summary>
adar,
/// <summary>
/// Adar I. Only in years with Adar II.
/// </summary>
adar_I = 12,
/// <summary>
/// Adar II. Only in years wirh Adar I.
/// </summary>
adar_II = 13,
};
/// <summary>
/// The method tells whether the year is a leap year.
/// </summary>
/// <param name="year">An integer representing the Hebrew year.
/// </param>
/// <returns>A boolean which is true if <paramref name="year"/> is
/// a leap year.
/// </returns>
public static bool is_leap_year(int year) {
return CCMath.mod(7*year+1, 19) < 7;
}
/// <summary>
/// The Method gives the number of the last month in a year, which
/// is equal with the number of month in a Hebrew year.
/// </summary>
/// <param name="year">An integer representing the Hebrew year.
/// </param>
/// <returns>An integer giving the number of the last month of the
/// Hebrew year, which is the same as the numbers of month in the
/// year.
/// </returns>
public static int last_month_of_year(int year) {
return is_leap_year(year) ? 13 : 12;
}
/// <summary>The method is a helper function.</summary>
/// <param name="year">An integer specifying the Hebrew year.
/// </param>
/// <returns>An integer representing the number of elapsed days
/// until the Hebrew year.</returns>
public static int elapsed_days(int year) {
int months_elapsed = CCMath.div(235*year-234, 19);
int r;
int d = CCMath.div_mod(out r, months_elapsed, 1080);
int parts_elapsed = 204 + 793 * r;
int hours_elapsed = 11 + 12 * months_elapsed +
793 * d + CCMath.div(parts_elapsed, 1080);
int day = 29*months_elapsed + CCMath.div(hours_elapsed, 24);
if (CCMath.mod(3*(day+1), 7) < 3) {
day += 1;
}
return day;
}
/// <summary>A method computing the delay of new year for the given
/// Hebrew year.
/// </summary>
/// <param name="year">An integer that gives the Hebrew year.
/// </param>
/// <returns>The new year delay in days of the given Hebrew year.
/// </returns>
public static int new_year_delay(int year) {
int ny1 = elapsed_days(year);
int ny2 = elapsed_days(year+1);
if (ny2 - ny1 == 356) {
return 2;
}
int ny0 = elapsed_days(year-1);
if (ny1 - ny0 == 382) {
return 1;
}
return 0;
}
/// <summary>
/// The method computes the last day of month (nummer of days in a
/// month) of the given Hebrew year.
/// </summary>
/// <param name="month">The Hebrew month, allowed value between
/// One and Thirteen.
/// </param>
/// <param name="year">An integer that gives the Hebrew year.
/// </param>
/// <returns>The number of the last day of the month of the given
/// Hebrew year, which gives automatically the number of days in the
/// month.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRange.Exception">
/// The exception is thrown if month not between One and Thirteen.
/// </exception>
public static int last_day_of_month(int month, int year) {
if (month < 1 || month > 13)
throw new System.ArgumentOutOfRangeException("month",
"Month should be between One and Thirteen.");
switch (month) {
case 2: return 29;
case 4: return 29;
case 6: return 29;
case 8:
if (!long_heshvan(year))
return 29;
break;
case 9:
if (short_kislev(year))
return 29;
break;
case 10: return 29;
case 12:
if (!is_leap_year(year))
return 29;
break;
case 13: return 29;
}
return 30;
}
/// <summary>
/// The functions checks whether the month Heshvan is a long one
/// in the given Hebrew year.
/// </summary>
/// <param name="year">An integer that gives the Hebrew year.
/// </param>
/// <returns>A boolean value: true if there is a long Heshvan
/// in the given Hebrew year; false otherwise.
/// </returns>
public static bool long_heshvan(int year) {
return CCMath.mod(days_in_year(year), 10) == 5;
}
/// <summary>
/// The functions checks whether the month Kislev is a short one
/// in the given Hebrew year.
/// </summary>
/// <param name="year">An integer that gives the Hebrew year.
/// </param>
/// <returns>A boolean value: true if there is a short Kislev
/// in the given Hebrew year; false otherwise.
/// </returns>
public static bool short_kislev(int year) {
return CCMath.mod(days_in_year(year), 10) == 3;
}
/// <summary>
/// The functions gives the number of days in the specified Hebrew
/// year.
/// </summary>
/// <param name="year">An integer that gives the Hebrew year.
/// </param>
/// <returns>The days of the Hebrew year as integer.
/// </returns>
public static int days_in_year(int year) {
return fixed_from_dmy(1, 7, year+1) -
fixed_from_dmy(1, 7, year);
}
/// <summary>
/// The method returns the fixed day number of the given Hebrew
/// date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Hebrew year.
/// </param>
/// <param name="year">An integer representing the Hebrew year.
/// Non-positive values are allowed also.
/// </param>
/// <returns>An integer value representing the fixed day number.
/// </returns>
public static int fixed_from_dmy(int day, int month, int year) {
int m;
int k = epoch-1;
k += elapsed_days(year);
k += new_year_delay(year);
if (month < 7) {
int l = last_month_of_year(year);
for (m = 7; m <= l; m++) {
k += last_day_of_month(m, year);
}
for (m = 1; m < month; m++) {
k += last_day_of_month(m, year);
}
}
else {
for (m = 7; m < month; m++) {
k += last_day_of_month(m, year);
}
}
k += day;
return k;
}
/// <summary>
/// The method computes the Hebrew year from a fixed day number.
/// </summary>
/// <param name="date">The fixed day number.
/// </param>
/// <returns>An integer value giving the Hebrew year of the date.
/// </returns>
public static int year_from_fixed(int date) {
int approx = (int)System.Math.Floor(
((double)(date - epoch))/(35975351.0/98496.0));
int y;
for (y = approx; date >= fixed_from_dmy(1, 7, y); y++) {}
return y-1;
}
/// <summary>
/// The method computes the Hebrew year and month from a fixed day
/// number.
/// </summary>
/// <param name="month">The output value giving the Hebrew month.
/// </param>
/// <param name="year">The output value giving the Hebrew year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void my_from_fixed(out int month, out int year,
int date)
{
year = year_from_fixed(date);
int start = date < fixed_from_dmy(1, 1, year) ? 7 : 1;
for (month = start;
date > fixed_from_dmy(last_day_of_month(month, year),
month, year);
month++)
{}
}
/// <summary>
/// The method computes the Hebrew year, month, and day from a
/// fixed day number.
/// </summary>
/// <param name="day">The output value returning the day of the
/// month.
/// </param>
/// <param name="month">The output value giving the Hebrew month.
/// </param>
/// <param name="year">The output value giving the Hebrew year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void dmy_from_fixed(out int day, out int month,
out int year, int date)
{
my_from_fixed(out month, out year, date);
day = date - fixed_from_dmy(1, month, year) + 1;
}
/// <summary>A method computing the Hebrew month from a fixed
/// day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the Hebrew month.
/// </returns>
public static int month_from_fixed(int date) {
int month, year;
my_from_fixed(out month, out year, date);
return month;
}
/// <summary>
/// A method computing the day of the month from a fixed day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the day of the month.
/// </returns>
public static int day_from_fixed(int date) {
int day, month, year;
dmy_from_fixed(out day, out month, out year, date);
return day;
}
/// <summary>
/// The method computes the difference between two Hebrew dates.
/// </summary>
/// <param name="dayA">The integer parameter gives the day of month
/// of the first date.
/// </param>
/// <param name="monthA">The integer parameter gives the Hebrew
/// month of the first date.
/// </param>
/// <param name="yearA">The integer parameter gives the Hebrew
/// year of the first date.
/// </param>
/// <param name="dayB">The integer parameter gives the day of month
/// of the second date.
/// </param>
/// <param name="monthB">The integer parameter gives the Hebrew
/// month of the second date.
/// </param>
/// <param name="yearB">The integer parameter gives the Hebrew
/// year of the second date.
/// </param>
/// <returns>An integer giving the difference of days from the first
/// the second date.
/// </returns>
public static int date_difference(int dayA, int monthA, int yearA,
int dayB, int monthB, int yearB)
{
return fixed_from_dmy(dayB, monthB, yearB) -
fixed_from_dmy(dayA, monthA, yearA);
}
/// <summary>
/// The method computes the number of the day in the year from
/// a Hebrew date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Hebrew year.
/// </param>
/// <param name="year">An integer representing the Hebrew year.
/// </param>
/// <returns>An integer value giving the number of the day in the
/// Hebrew year, counting from 1.
/// </returns>
public static int day_number(int day, int month, int year) {
return date_difference(1, 7, year,
day, month, year) + 1;
}
/// <summary>
/// The method computes the days remaining in the given Hebrew
/// year from a Hebrew date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Hebrew year.
/// </param>
/// <param name="year">An integer representing the Hebrew year.
/// </param>
/// <returns>An integer value giving the number of days remaining in
/// the Hebrew year.
/// </returns>
public static int days_remaining(int day, int month, int year) {
return date_difference(day, month, year,
1, 7, year+1)-1;
}
} // class HebrewCalendar
/// <summary>
/// A class encapsulating the functions of the Islamic calendar as static
/// methods.
/// </summary>
/// <remarks>
/// <para>There is no difference here in using Hijri or Islamic calendar.
/// </para>
/// <para>The epoch of the Islamic calendar isn't fixed, because we cannot
/// surely say today, when the crescent of the new moon has been observed
/// around the July 16, 622 C.E. Julian. Even today the start and end of
/// the month Ramadan is defined by religous authorities. So the calendar
/// can be offset by two days.
/// </para>
/// <para>
/// We don't support the offset here, however we changed the epoch from
/// "Calendrical Calculations" to value, that .Net seems to be using.
/// </para>
/// <para>
/// This class is not compatible to
/// <see cref="T:System.Globalization.HijriCalendar"/>.
/// </para>
/// <seealso cref="T:CCFixed"/>
/// </remarks>
internal class CCHijriCalendar {
/// <summary>An integer defining the epoch of the Gregorian calendar
/// as fixed day number.</summary>
/// <remarks>
/// <para>
/// The epoch is given as 16 July 622 C.E. Julian (R.D. 227015)
/// in Calendrical Calculations, the approximate date of
/// the emigration of
/// Muhammed to Medina. However there is no way to determine today
/// the observation of the crescent of the new moon in July 622 C.E.
/// (Julian). So there is some variability in the epoch.
/// Religous authorities determine the epoch by observing the
/// crescent of the new moon for the month Ramadan, so there might
/// be an offsets by two days of the epoch.
/// </para>
/// <para>Windows
/// supports an AddHijriDate parameter in the registry to adapt
/// for it. It seems that the .NET implementation of
/// HijriCalendar uses an epoch of 227014, so we use it here. The
/// ArgumentOutOfRangeException gives July, 18 622 as epoch,
/// which is 227014 supporting our theory.
/// </para>
/// </remarks>
const int epoch = 227014;
/// <summary>The enumeration defines the months of the Islamic
/// calendar.
/// </summary>
public enum Month {
/// <summary>
/// Muharram.
/// </summary>
muharram = 1,
/// <summary>
/// Safar.
/// </summary>
safar,
/// <summary>
/// Rabi I.
/// </summary>
rabi_I,
/// <summary>
/// Rabi II.
/// </summary>
rabi_II,
/// <summary>
/// Jumada I.
/// </summary>
jumada_I,
/// <summary>
/// Jumada II.
/// </summary>
jumada_II,
/// <summary>
/// Rajab.
/// </summary>
rajab,
/// <summary>
/// Shaban.
/// </summary>
shaban,
/// <summary>
/// Ramadan.
/// </summary>
ramadan,
/// <summary>
/// Shawwal.
/// </summary>
shawwal,
/// <summary>
/// Dhu Al-Quada.
/// </summary>
dhu_al_quada,
/// <summary>
/// Dhu Al-Hijja.
/// </summary>
dhu_al_hijja,
};
/// <summary>
/// The method tells whether the year is a leap year.
/// </summary>
/// <param name="year">An integer representing the Islamic year.
/// </param>
/// <returns>A boolean which is true if <paramref name="year"/> is
/// a leap year.
/// </returns>
public static bool is_leap_year(int year) {
return CCMath.mod(14+11*year, 30) < 11;
}
/// <summary>
/// The method returns the fixed day number of the given Islamic
/// date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Islamic year.
/// </param>
/// <param name="year">An integer representing the Islamic year.
/// Non-positive values are allowed also.
/// </param>
/// <returns>An integer value representing the fixed day number.
/// </returns>
public static int fixed_from_dmy(int day, int month, int year) {
int k = epoch - 1;
k += 354 * (year-1);
k += CCMath.div(3+11*year, 30);
k += (int)System.Math.Ceiling(29.5 * (double)(month-1));
k += day;
return k;
}
/// <summary>
/// The method computes the Islamic year from a fixed day number.
/// </summary>
/// <param name="date">The fixed day number.
/// </param>
/// <returns>An integer value giving the Islamic year of the date.
/// </returns>
public static int year_from_fixed(int date) {
return CCMath.div(30*(date-epoch)+10646, 10631);
}
/// <summary>
/// The method computes the Islamic year and month from a fixed day
/// number.
/// </summary>
/// <param name="month">The output value giving the Islamic month.
/// </param>
/// <param name="year">The output value giving the Islamic year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void my_from_fixed(out int month, out int year, int date)
{
year = year_from_fixed(date);
int m = 1+(int)System.Math.Ceiling(
((double)(date-29-fixed_from_dmy(1,1,year)))/29.5);
month = m < 12 ? m : 12;
}
/// <summary>
/// The method computes the Islamic year, month, and day from a
/// fixed day number.
/// </summary>
/// <param name="day">The output value returning the day of the
/// month.
/// </param>
/// <param name="month">The output value giving the Islamic month.
/// </param>
/// <param name="year">The output value giving the Islamic year.
/// </param>
/// <param name="date">An integer value specifying the fixed day
/// number.</param>
public static void dmy_from_fixed(out int day, out int month,
out int year, int date)
{
my_from_fixed(out month, out year, date);
day = date - fixed_from_dmy(1, month, year) + 1;
}
/// <summary>A method computing the Islamic month from a fixed
/// day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the Islamic month.
/// </returns>
public static int month_from_fixed(int date) {
int month, year;
my_from_fixed(out month, out year, date);
return month;
}
/// <summary>
/// A method computing the day of the month from a fixed day number.
/// </summary>
/// <param name="date">An integer specifying the fixed day number.
/// </param>
/// <returns>An integer value representing the day of the month.
/// </returns>
public static int day_from_fixed(int date) {
int day;
int month;
int year;
dmy_from_fixed(out day, out month, out year, date);
return day;
}
/// <summary>
/// The method computes the difference between two Islamic dates.
/// </summary>
/// <param name="dayA">The integer parameter gives the day of month
/// of the first date.
/// </param>
/// <param name="monthA">The integer parameter gives the Islamic
/// month of the first date.
/// </param>
/// <param name="yearA">The integer parameter gives the Islamic
/// year of the first date.
/// </param>
/// <param name="dayB">The integer parameter gives the day of month
/// of the second date.
/// </param>
/// <param name="monthB">The integer parameter gives the Islamic
/// month of the second date.
/// </param>
/// <param name="yearB">The integer parameter gives the Islamic
/// year of the second date.
/// </param>
/// <returns>An integer giving the difference of days from the first
/// the second date.
/// </returns>
public static int date_difference(int dayA, int monthA, int yearA,
int dayB, int monthB, int yearB)
{
return fixed_from_dmy(dayB, monthB, yearB) -
fixed_from_dmy(dayA, monthA, yearA);
}
/// <summary>
/// The method computes the number of the day in the year from
/// a Islamic date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Islamic year.
/// </param>
/// <param name="year">An integer representing the Islamic year.
/// </param>
/// <returns>An integer value giving the number of the day in the
/// Islamic year, counting from 1.
/// </returns>
public static int day_number(int day, int month, int year) {
return date_difference(31, 12, year-1, day, month, year);
}
/// <summary>
/// The method computes the days remaining in the given Islamic
/// year from a Islamic date.
/// </summary>
/// <param name="day">An integer representing the day of the month,
/// counting from 1.
/// </param>
/// <param name="month">An integer representing the month in the
/// Islamic year.
/// </param>
/// <param name="year">An integer representing the Islamic year.
/// Non-positive values are allowed also.
/// </param>
/// <returns>An integer value giving the number of days remaining in
/// the Islamic year.
/// </returns>
public static int days_remaining(int day, int month, int year) {
return date_difference(day, month, year,31, 12, year);
}
} // class CCHijriCalendar
internal class CCEastAsianLunisolarCalendar
{
public static int fixed_from_dmy (int day, int month, int year)
{
/*
int k = epoch - 1;
k += 354 * (year - 1);
k += CCMath.div (3+11*year, 30);
k += (int) Math.Ceiling(29.53 * (double)(month-1));
k += day;
return k;
*/
throw new Exception ("fixed_from_dmy");
}
public static int year_from_fixed (int date)
{
throw new Exception ("year_from_fixed");
}
public static void my_from_fixed(out int month, out int year, int date)
{
/*
year = year_from_fixed (date);
int m = 1+(int)System.Math.Ceiling(
((double)(date-29-fixed_from_dmy(1,1,year)))/29.5);
month = m < 12 ? m : 12;
*/
throw new Exception ("my_from_fixed");
}
public static void dmy_from_fixed(out int day, out int month,
out int year, int date)
{
/*
my_from_fixed (out month, out year, date);
day = date - fixed_from_dmy (1, month, year) + 1;
*/
throw new Exception ("dmy_from_fixed");
}
public static DateTime AddMonths (DateTime date, int months)
{
throw new Exception ("AddMonths");
}
public static DateTime AddYears (DateTime date, int years)
{
throw new Exception ("AddYears");
}
public static int GetDayOfMonth (DateTime date)
{
throw new Exception ("GetDayOfMonth");
}
public static int GetDayOfYear (DateTime date)
{
throw new Exception ("GetDayOfYear");
}
public static int GetDaysInMonth (int gyear, int month)
{
throw new Exception ("GetDaysInMonth");
}
public static int GetDaysInYear (int year)
{
throw new Exception ("GetDaysInYear");
}
public static int GetMonth (DateTime date)
{
throw new Exception ("GetMonth");
}
public static bool IsLeapMonth (int gyear, int month)
{
int goldenNumber = gyear % 19;
bool chu = false;
bool leap = false;
double s = 0;
for (int y = 0; y < goldenNumber; y++) {
for (int l = 0, m = 1; m <= month; m++) {
if (leap) {
l += 30;
leap = false;
if (y == goldenNumber && m == month)
return true;
} else {
l += chu ? 30 : 29;
chu = !chu;
s += 30.44;
if (s - l > 29)
leap = true;
}
}
}
return false;
}
public static bool IsLeapYear (int gyear)
{
// FIXME: it is still wrong.
int d = gyear % 19;
switch (d) {
case 0: case 3: case 6: case 9: case 11: case 14: case 17:
return true;
default:
return false;
}
/*
int goldenNumber = (gyear - 1900) % 19;
int epact = 29;
bool leap = false;
while (goldenNumber-- >= 0) {
epact += 11;
leap = epact > 30;
if (epact > 30)
epact -= 30;
}
return leap;
*/
}
public static DateTime ToDateTime (int year, int month, int day, int hour, int minute, int second, int millisecond)
{
throw new Exception ("ToDateTime");
}
}
/// <summary>
/// A class that supports the Gregorian based calendars with other eras
/// (e.g. <see cref="T:System.Gloablization.JapaneseCalendar"/>).
/// </summary>
[System.Serializable]
internal class CCGregorianEraHandler {
/// <summary>
/// A struct that represents a single era.
/// </summary>
[System.Serializable]
struct Era {
/// <summary>
/// The integer number identifying the era.
/// </summary>
private int _nr;
/// <value>
/// A get-only property that gives the era integer number.
/// </value>
public int Nr { get { return _nr; } }
/// <summary>This integer gives the first day of the era as
/// fixed day number.
/// </summary>
private int _start; // inclusive
/// <summary>
/// This integer gives the gregorian year of the
/// <see cref="M:_start"/> value.
/// </summary>
private int _gregorianYearStart;
/// <summary>
/// This integer gives the last day of the era as fixed day
/// number.
/// </summary>
private int _end; // inclusive
/// <summary>
/// This integer gives the largest year number of this era.
/// </summary>
private int _maxYear;
/// <summary>
/// This constructor creates the era structure.
/// </summary>
/// <param name="nr">The integer number of the era.
/// </param>
/// <param name="start">The fixed day number defining the
/// first day of the era.
/// </param>
/// <param name="end">The fixed day number that defines the
/// last day of the era.
/// </param>
public Era(int nr, int start, int end) {
if (nr == 0)
throw new System.ArgumentException(
"Era number shouldn't be zero.");
_nr = nr;
if (start > end) {
throw new System.ArgumentException(
"Era should start before end.");
}
_start = start;
_end = end;
_gregorianYearStart =
CCGregorianCalendar.year_from_fixed(_start);
int gregorianYearEnd =
CCGregorianCalendar.year_from_fixed(_end);
_maxYear = gregorianYearEnd - _gregorianYearStart + 1;
}
/// <summary>
/// This method computes the Gregorian year from the year
/// of this era.
/// </summary>
/// <param name="year">An integer giving the year in the
/// era.
/// </param>
/// <returns>
/// The Gregorian year as integer.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// The exception is thrown if the year isn't valid in this
/// era.
/// </exception>
public int GregorianYear(int year) {
if (year < 1 || year > _maxYear) {
System.IO.StringWriter sw =
new System.IO.StringWriter();
sw.Write(
"Valid Values are between " +
"{0} and {1}, inclusive.",
1, _maxYear);
throw new System.ArgumentOutOfRangeException(
"year", sw.ToString());
}
return year + _gregorianYearStart - 1;
}
/// <summary>
/// This function checks wether the given fixed day number is
/// ion the time span of the era.
/// </summary>
/// <param name="date">An integer giving the fixed day
/// number.
/// </param>
/// <returns>A boolean: true if the argument is in the time
/// span of the era.
/// </returns>
public bool Covers(int date) {
return _start <= date && date <= _end;
}
/// <summary>
/// This function returns the year of the era and sets
/// the era in an output parameter.
/// </summary>
/// <param name="era">An output parameter returning the
/// era number.
/// </param>
/// <param name="date">An integer giving the fixed day
/// number.
/// </param>
/// <returns>An integer giving the year of the era.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// The exception is thrown if date is outside of the time
/// span of the era.
/// </exception>
public int EraYear(out int era, int date) {
if (!Covers(date))
throw new System.ArgumentOutOfRangeException(
"date",
"Time was out of Era range.");
int gregorianYear =
CCGregorianCalendar.year_from_fixed(date);
era = _nr;
return gregorianYear - _gregorianYearStart + 1;
}
} // struct Era
/// <summary>
/// A private member storing the eras in a
/// <see cref="T:System.Collections.SortedList"/>.
/// </summary>
private SortedList _Eras;
/// <value>
/// The property returns the era numbers as an array of integers.
/// </value>
public int[] Eras {
get {
int[] a = new int[_Eras.Count];
for (int i = 0; i < _Eras.Count; i++) {
Era e = (Era)_Eras.GetByIndex(i);
a[i] = e.Nr;
}
return a;
}
}
/// <summary>
/// Constructor.
/// </summary>
public CCGregorianEraHandler() {
_Eras = new SortedList();
}
/// <summary>
/// Method adds an era to the GregorianEraHandler instance.
/// </summary>
/// <param name="nr">The integer number of the era.
/// </param>
/// <param name="rd_start">The fixed day number defining the
/// first day of the era.
/// </param>
/// <param name="rd_end">The fixed day number that defines the
/// last day of the era.
/// </param>
public void appendEra(int nr, int rd_start, int rd_end) {
Era era = new Era(nr, rd_start, rd_end);
_Eras[(System.Object)nr] = era;
}
/// <summary>
/// Method adds a yet not-ended era to the GregorianEraHandler
/// instance.
/// </summary>
/// <param name="nr">The integer number of the era.
/// </param>
/// <param name="rd_start">The fixed day number defining the
/// first day of the era.
/// </param>
public void appendEra(int nr, int rd_start) {
appendEra(nr, rd_start,
CCFixed.FromDateTime(DateTime.MaxValue));
}
/// <summary>
/// This method computes the Gregorian year from the year
/// of the given era.
/// </summary>
/// <param name="year">An integer giving the year in the
/// era.
/// </param>
/// <param name="era">An integer giving the era number.
/// </param>
/// <returns>
/// The Gregorian year as integer.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// The exception is thrown if the year isn't valid in this
/// era.
/// </exception>
public int GregorianYear(int year, int era) {
Era e = (Era)_Eras[(System.Object)era];
return e.GregorianYear(year);
}
/// <summary>
/// This function returns the year of the era and sets
/// the era in an output parameter.
/// </summary>
/// <param name="era">An output parameter returning the
/// era number.
/// </param>
/// <param name="date">An integer giving the fixed day
/// number.
/// </param>
/// <returns>An integer giving the year of the era.
/// </returns>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// The exception is thrown if the fixed day number is outside of the
/// time spans of all eras.
/// </exception>
public int EraYear(out int era, int date)
{
IList list = _Eras.GetValueList();
foreach (Era e in list) {
if (e.Covers(date))
return e.EraYear(out era, date);
}
throw new System.ArgumentOutOfRangeException("date",
"Time value was out of era range.");
}
/// <summary>
/// The method checks whether a given
/// <see cref="T:System.DateTime"/> is covered by any era.
/// </summary>
/// <param name="time">A
/// <see cref="T:System.DateTime"/> giving the date and time.
/// </param>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// The exception is thrown if the argument isn't inside the time
/// span of any era.
/// </exception>
public void CheckDateTime(System.DateTime time) {
int date = CCFixed.FromDateTime(time);
if (!ValidDate(date))
throw new System.ArgumentOutOfRangeException("time",
"Time value was out of era range.");
}
/// <summary>
/// The method tests whether a given
/// fixed day number is covered by any era.
/// </summary>
/// <param name="date">An integer representing the fixed day number.
/// </param>
/// <returns> A boolean is returned: true if the argument is inside
/// the time span of one era; false otherwise.
/// </returns>
public bool ValidDate(int date) {
IList list = _Eras.GetValueList();
foreach (Era e in list) {
if (e.Covers(date))
return true;
}
return false;
}
/// <summary>
/// The method tests, whether the era number does exist.
/// </summary>
/// <param name="era">An integer giving the era number.
/// </param>
/// <returns>A boole value: True if the era number does exist;
/// false otherwise.
/// </returns>
public bool ValidEra(int era) {
return _Eras.Contains((System.Object)era);
}
} // class CCGregorianEraHandler
// FIXME: remove this class. It should be identical to CCGregorianEraHandler
[System.Serializable]
internal class CCEastAsianLunisolarEraHandler
{
[Serializable]
struct Era
{
private int _nr; // era index
public int Nr {
get { return _nr; }
}
private int _start; // inclusive
private int _gregorianYearStart;
private int _end; // inclusive
private int _maxYear;
public Era (int nr, int start, int end)
{
if (nr == 0)
throw new ArgumentException ("Era number shouldn't be zero.");
_nr = nr;
if (start > end)
throw new ArgumentException ("Era should start before end.");
_start = start;
_end = end;
_gregorianYearStart = CCGregorianCalendar.year_from_fixed (_start);
int gregorianYearEnd = CCGregorianCalendar.year_from_fixed (_end);
_maxYear = gregorianYearEnd - _gregorianYearStart + 1;
}
public int GregorianYear (int year)
{
if (year < 1 || year > _maxYear)
throw new ArgumentOutOfRangeException ("year", String.Format ("Valid Values are between {0} and {1}, inclusive.", 1, _maxYear));
return year + _gregorianYearStart - 1;
}
public bool Covers (int date) {
return _start <= date && date <= _end;
}
public int EraYear (out int era, int date) {
if (!Covers (date))
throw new ArgumentOutOfRangeException ("date", "Time was out of Era range.");
int gregorianYear = CCGregorianCalendar.year_from_fixed (date);
era = _nr;
return gregorianYear - _gregorianYearStart + 1;
}
}
private SortedList _Eras;
public int [] Eras
{
get {
int[] a = new int [_Eras.Count];
for (int i = 0; i < _Eras.Count; i++) {
Era e = (Era) _Eras.GetByIndex (i);
a[i] = e.Nr;
}
return a;
}
}
public CCEastAsianLunisolarEraHandler ()
{
_Eras = new SortedList ();
}
public void appendEra (int nr, int rd_start, int rd_end)
{
Era era = new Era (nr, rd_start, rd_end);
_Eras [nr] = era;
}
public void appendEra (int nr, int rd_start)
{
appendEra (nr, rd_start, CCFixed.FromDateTime (DateTime.MaxValue));
}
public int GregorianYear (int year, int era)
{
Era e = (Era) _Eras [era];
return e.GregorianYear (year);
}
public int EraYear (out int era, int date)
{
foreach (Era e in _Eras.Values)
if (e.Covers (date))
return e.EraYear (out era, date);
throw new ArgumentOutOfRangeException ("date", "Time value was out of era range.");
}
public void CheckDateTime (DateTime time)
{
int date = CCFixed.FromDateTime (time);
if (!ValidDate (date))
throw new ArgumentOutOfRangeException ("time", "Time value was out of era range.");
}
public bool ValidDate (int date)
{
foreach (Era e in _Eras.Values) {
if (e.Covers (date))
return true;
}
return false;
}
public bool ValidEra (int era)
{
return _Eras.Contains (era);
}
}
} // namespace System.Globalization
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