// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the MIT license. // See the LICENSE file in the project root for more information. namespace System.Globalization { using System; using System.Diagnostics; using System.Diagnostics.Contracts; //////////////////////////////////////////////////////////////////////////// // // Notes about PersianCalendar // //////////////////////////////////////////////////////////////////////////// // Modern Persian calendar is a solar observation based calendar. Each new year begins on the day when the vernal equinox occurs before noon. // The epoch is the date of the vernal equinox prior to the epoch of the Islamic calendar (March 19, 622 Julian or March 22, 622 Gregorian) // There is no Persian year 0. Ordinary years have 365 days. Leap years have 366 days with the last month (Esfand) gaining the extra day. /* ** Calendar support range: ** Calendar Minimum Maximum ** ========== ========== ========== ** Gregorian 0622/03/22 9999/12/31 ** Persian 0001/01/01 9378/10/13 */ [Serializable] public class PersianCalendar : Calendar { public static readonly int PersianEra = 1; internal static long PersianEpoch = new DateTime(622, 3, 22).Ticks / GregorianCalendar.TicksPerDay; const int ApproximateHalfYear = 180; internal const int DatePartYear = 0; internal const int DatePartDayOfYear = 1; internal const int DatePartMonth = 2; internal const int DatePartDay = 3; internal const int MonthsPerYear = 12; internal static int[] DaysToMonth = { 0, 31, 62, 93, 124, 155, 186, 216, 246, 276, 306, 336, 366 }; internal const int MaxCalendarYear = 9378; internal const int MaxCalendarMonth = 10; internal const int MaxCalendarDay = 13; // Persian calendar (year: 1, month: 1, day:1 ) = Gregorian (year: 622, month: 3, day: 22) // This is the minimal Gregorian date that we support in the PersianCalendar. internal static DateTime minDate = new DateTime(622, 3, 22); internal static DateTime maxDate = DateTime.MaxValue; /*=================================GetDefaultInstance========================== **Action: Internal method to provide a default intance of PersianCalendar. Used by NLS+ implementation ** and other calendars. **Returns: **Arguments: **Exceptions: ============================================================================*/ /* internal static Calendar GetDefaultInstance() { if (m_defaultInstance == null) { m_defaultInstance = new PersianCalendar(); } return (m_defaultInstance); } */ public override DateTime MinSupportedDateTime { get { return (minDate); } } public override DateTime MaxSupportedDateTime { get { return (maxDate); } } // Return the type of the Persian calendar. // public override CalendarAlgorithmType AlgorithmType { get { return CalendarAlgorithmType.SolarCalendar; } } // Construct an instance of Persian calendar. public PersianCalendar() { } internal override int BaseCalendarID { get { return (CAL_GREGORIAN); } } internal override int ID { get { return (CAL_PERSIAN); } } /*=================================GetAbsoluteDatePersian========================== **Action: Gets the Absolute date for the given Persian date. The absolute date means ** the number of days from January 1st, 1 A.D. **Returns: **Arguments: **Exceptions: ============================================================================*/ long GetAbsoluteDatePersian(int year, int month, int day) { if (year >= 1 && year <= MaxCalendarYear && month >= 1 && month <= 12) { int ordinalDay = DaysInPreviousMonths(month) + day - 1; // day is one based, make 0 based since this will be the number of days we add to beginning of year below int approximateDaysFromEpochForYearStart = (int)(CalendricalCalculationsHelper.MeanTropicalYearInDays * (year - 1)); long yearStart = CalendricalCalculationsHelper.PersianNewYearOnOrBefore(PersianEpoch + approximateDaysFromEpochForYearStart + ApproximateHalfYear); yearStart += ordinalDay; return yearStart; } throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay")); } static internal void CheckTicksRange(long ticks) { if (ticks < minDate.Ticks || ticks > maxDate.Ticks) { throw new ArgumentOutOfRangeException( "time", String.Format( CultureInfo.InvariantCulture, Environment.GetResourceString("ArgumentOutOfRange_CalendarRange"), minDate, maxDate)); } } static internal void CheckEraRange(int era) { if (era != CurrentEra && era != PersianEra) { throw new ArgumentOutOfRangeException(nameof(era), Environment.GetResourceString("ArgumentOutOfRange_InvalidEraValue")); } } static internal void CheckYearRange(int year, int era) { CheckEraRange(era); if (year < 1 || year > MaxCalendarYear) { throw new ArgumentOutOfRangeException( nameof(year), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, MaxCalendarYear)); } } static internal void CheckYearMonthRange(int year, int month, int era) { CheckYearRange(year, era); if (year == MaxCalendarYear) { if (month > MaxCalendarMonth) { throw new ArgumentOutOfRangeException( nameof(month), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, MaxCalendarMonth)); } } if (month < 1 || month > 12) { throw new ArgumentOutOfRangeException(nameof(month), Environment.GetResourceString("ArgumentOutOfRange_Month")); } } static int MonthFromOrdinalDay(int ordinalDay) { Debug.Assert(ordinalDay <= 366); int index = 0; while (ordinalDay > DaysToMonth[index]) index++; return index; } static int DaysInPreviousMonths(int month) { Debug.Assert(1 <= month && month <= 12); --month; // months are one based but for calculations use 0 based return DaysToMonth[month]; } /*=================================GetDatePart========================== **Action: Returns a given date part of this DateTime. This method is used ** to compute the year, day-of-year, month, or day part. **Returns: **Arguments: **Exceptions: ArgumentException if part is incorrect. ============================================================================*/ internal int GetDatePart(long ticks, int part) { long NumDays; // The calculation buffer in number of days. CheckTicksRange(ticks); // // Get the absolute date. The absolute date is the number of days from January 1st, 1 A.D. // 1/1/0001 is absolute date 1. // NumDays = ticks / GregorianCalendar.TicksPerDay + 1; // // Calculate the appromixate Persian Year. // long yearStart = CalendricalCalculationsHelper.PersianNewYearOnOrBefore(NumDays); int y = (int)(Math.Floor(((yearStart - PersianEpoch) / CalendricalCalculationsHelper.MeanTropicalYearInDays) + 0.5)) + 1; Debug.Assert(y >= 1); if (part == DatePartYear) { return y; } // // Calculate the Persian Month. // int ordinalDay = (int)(NumDays - CalendricalCalculationsHelper.GetNumberOfDays(this.ToDateTime(y, 1, 1, 0, 0, 0, 0, 1))); if (part == DatePartDayOfYear) { return ordinalDay; } int m = MonthFromOrdinalDay(ordinalDay); Debug.Assert(ordinalDay >= 1); Debug.Assert(m >= 1 && m <= 12); if (part == DatePartMonth) { return m; } int d = ordinalDay - DaysInPreviousMonths(m); Debug.Assert(1 <= d); Debug.Assert(d <= 31); // // Calculate the Persian Day. // if (part == DatePartDay) { return (d); } // Incorrect part value. throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_DateTimeParsing")); } // Returns the DateTime resulting from adding the given number of // months to the specified DateTime. The result is computed by incrementing // (or decrementing) the year and month parts of the specified DateTime by // value months, and, if required, adjusting the day part of the // resulting date downwards to the last day of the resulting month in the // resulting year. The time-of-day part of the result is the same as the // time-of-day part of the specified DateTime. // // In more precise terms, considering the specified DateTime to be of the // form y / m / d + t, where y is the // year, m is the month, d is the day, and t is the // time-of-day, the result is y1 / m1 / d1 + t, // where y1 and m1 are computed by adding value months // to y and m, and d1 is the largest value less than // or equal to d that denotes a valid day in month m1 of year // y1. // public override DateTime AddMonths(DateTime time, int months) { if (months < -120000 || months > 120000) { throw new ArgumentOutOfRangeException( nameof(months), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), -120000, 120000)); } Contract.EndContractBlock(); // Get the date in Persian calendar. int y = GetDatePart(time.Ticks, DatePartYear); int m = GetDatePart(time.Ticks, DatePartMonth); int d = GetDatePart(time.Ticks, DatePartDay); int i = m - 1 + months; if (i >= 0) { m = i % 12 + 1; y = y + i / 12; } else { m = 12 + (i + 1) % 12; y = y + (i - 11) / 12; } int days = GetDaysInMonth(y, m); if (d > days) { d = days; } long ticks = GetAbsoluteDatePersian(y, m, d) * TicksPerDay + time.Ticks % TicksPerDay; Calendar.CheckAddResult(ticks, MinSupportedDateTime, MaxSupportedDateTime); return (new DateTime(ticks)); } // Returns the DateTime resulting from adding the given number of // years to the specified DateTime. The result is computed by incrementing // (or decrementing) the year part of the specified DateTime by value // years. If the month and day of the specified DateTime is 2/29, and if the // resulting year is not a leap year, the month and day of the resulting // DateTime becomes 2/28. Otherwise, the month, day, and time-of-day // parts of the result are the same as those of the specified DateTime. // public override DateTime AddYears(DateTime time, int years) { return (AddMonths(time, years * 12)); } // Returns the day-of-month part of the specified DateTime. The returned // value is an integer between 1 and 31. // public override int GetDayOfMonth(DateTime time) { return (GetDatePart(time.Ticks, DatePartDay)); } // Returns the day-of-week part of the specified DateTime. The returned value // is an integer between 0 and 6, where 0 indicates Sunday, 1 indicates // Monday, 2 indicates Tuesday, 3 indicates Wednesday, 4 indicates // Thursday, 5 indicates Friday, and 6 indicates Saturday. // public override DayOfWeek GetDayOfWeek(DateTime time) { return ((DayOfWeek)((int)(time.Ticks / TicksPerDay + 1) % 7)); } // Returns the day-of-year part of the specified DateTime. The returned value // is an integer between 1 and 366. // public override int GetDayOfYear(DateTime time) { return (GetDatePart(time.Ticks, DatePartDayOfYear)); } // Returns the number of days in the month given by the year and // month arguments. // public override int GetDaysInMonth(int year, int month, int era) { CheckYearMonthRange(year, month, era); if ((month==MaxCalendarMonth) && (year==MaxCalendarYear)) { return MaxCalendarDay; } int daysInMonth = DaysToMonth[month] - DaysToMonth[month - 1]; if ((month == MonthsPerYear) && !IsLeapYear(year)) { Debug.Assert(daysInMonth == 30); --daysInMonth; } return daysInMonth; } // Returns the number of days in the year given by the year argument for the current era. // public override int GetDaysInYear(int year, int era) { CheckYearRange(year, era); if (year==MaxCalendarYear) { return DaysToMonth[MaxCalendarMonth-1] + MaxCalendarDay; } // Common years have 365 days. Leap years have 366 days. return (IsLeapYear(year, CurrentEra) ? 366: 365); } // Returns the era for the specified DateTime value. public override int GetEra(DateTime time) { CheckTicksRange(time.Ticks); return (PersianEra); } public override int[] Eras { get { return (new int[] {PersianEra}); } } // Returns the month part of the specified DateTime. The returned value is an // integer between 1 and 12. // public override int GetMonth(DateTime time) { return (GetDatePart(time.Ticks, DatePartMonth)); } // Returns the number of months in the specified year and era. public override int GetMonthsInYear(int year, int era) { CheckYearRange(year, era); if (year==MaxCalendarYear) { return MaxCalendarMonth; } return (12); } // Returns the year part of the specified DateTime. The returned value is an // integer between 1 and MaxCalendarYear. // public override int GetYear(DateTime time) { return (GetDatePart(time.Ticks, DatePartYear)); } // Checks whether a given day in the specified era is a leap day. This method returns true if // the date is a leap day, or false if not. // public override bool IsLeapDay(int year, int month, int day, int era) { // The year/month/era value checking is done in GetDaysInMonth(). int daysInMonth = GetDaysInMonth(year, month, era); if (day < 1 || day > daysInMonth) { throw new ArgumentOutOfRangeException( nameof(day), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Day"), daysInMonth, month)); } return (IsLeapYear(year, era) && month == 12 && day == 30); } // Returns the leap month in a calendar year of the specified era. This method returns 0 // if this calendar does not have leap month, or this year is not a leap year. // public override int GetLeapMonth(int year, int era) { CheckYearRange(year, era); return (0); } // Checks whether a given month in the specified era is a leap month. This method returns true if // month is a leap month, or false if not. // public override bool IsLeapMonth(int year, int month, int era) { CheckYearMonthRange(year, month, era); return (false); } // Checks whether a given year in the specified era is a leap year. This method returns true if // year is a leap year, or false if not. // public override bool IsLeapYear(int year, int era) { CheckYearRange(year, era); if (year == MaxCalendarYear) { return false; } return (GetAbsoluteDatePersian(year + 1, 1, 1) - GetAbsoluteDatePersian(year, 1, 1)) == 366; } // Returns the date and time converted to a DateTime value. Throws an exception if the n-tuple is invalid. // public override DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era) { // The year/month/era checking is done in GetDaysInMonth(). int daysInMonth = GetDaysInMonth(year, month, era); if (day < 1 || day > daysInMonth) { BCLDebug.Log("year = " + year + ", month = " + month + ", day = " + day); throw new ArgumentOutOfRangeException( nameof(day), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Day"), daysInMonth, month)); } long lDate = GetAbsoluteDatePersian(year, month, day); if (lDate >= 0) { return (new DateTime(lDate * GregorianCalendar.TicksPerDay + TimeToTicks(hour, minute, second, millisecond))); } else { throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay")); } } private const int DEFAULT_TWO_DIGIT_YEAR_MAX = 1410; public override int TwoDigitYearMax { get { if (twoDigitYearMax == -1) { twoDigitYearMax = GetSystemTwoDigitYearSetting(ID, DEFAULT_TWO_DIGIT_YEAR_MAX); } return (twoDigitYearMax); } set { VerifyWritable(); if (value < 99 || value > MaxCalendarYear) { throw new ArgumentOutOfRangeException( nameof(value), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 99, MaxCalendarYear)); } twoDigitYearMax = value; } } public override int ToFourDigitYear(int year) { if (year < 0) { throw new ArgumentOutOfRangeException(nameof(year), Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum")); } Contract.EndContractBlock(); if (year < 100) { return (base.ToFourDigitYear(year)); } if (year > MaxCalendarYear) { throw new ArgumentOutOfRangeException( nameof(year), String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, MaxCalendarYear)); } return (year); } } }