// 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. using System; using System.Diagnostics.Contracts; using System.Runtime.Serialization; using System.Threading; namespace System.Globalization { // Gregorian Calendars use Era Info [Serializable] internal class EraInfo { internal int era; // The value of the era. internal long ticks; // The time in ticks when the era starts internal int yearOffset; // The offset to Gregorian year when the era starts. // Gregorian Year = Era Year + yearOffset // Era Year = Gregorian Year - yearOffset internal int minEraYear; // Min year value in this era. Generally, this value is 1, but this may // be affected by the DateTime.MinValue; internal int maxEraYear; // Max year value in this era. (== the year length of the era + 1) [OptionalField(VersionAdded = 4)] internal String eraName; // The era name [OptionalField(VersionAdded = 4)] internal String abbrevEraName; // Abbreviated Era Name [OptionalField(VersionAdded = 4)] internal String englishEraName; // English era name internal EraInfo(int era, int startYear, int startMonth, int startDay, int yearOffset, int minEraYear, int maxEraYear) { this.era = era; this.yearOffset = yearOffset; this.minEraYear = minEraYear; this.maxEraYear = maxEraYear; this.ticks = new DateTime(startYear, startMonth, startDay).Ticks; } internal EraInfo(int era, int startYear, int startMonth, int startDay, int yearOffset, int minEraYear, int maxEraYear, String eraName, String abbrevEraName, String englishEraName) { this.era = era; this.yearOffset = yearOffset; this.minEraYear = minEraYear; this.maxEraYear = maxEraYear; this.ticks = new DateTime(startYear, startMonth, startDay).Ticks; this.eraName = eraName; this.abbrevEraName = abbrevEraName; this.englishEraName = englishEraName; } } // This calendar recognizes two era values: // 0 CurrentEra (AD) // 1 BeforeCurrentEra (BC) [Serializable] internal class GregorianCalendarHelper { // 1 tick = 100ns = 10E-7 second // Number of ticks per time unit internal const long TicksPerMillisecond = 10000; internal const long TicksPerSecond = TicksPerMillisecond * 1000; internal const long TicksPerMinute = TicksPerSecond * 60; internal const long TicksPerHour = TicksPerMinute * 60; internal const long TicksPerDay = TicksPerHour * 24; // Number of milliseconds per time unit internal const int MillisPerSecond = 1000; internal const int MillisPerMinute = MillisPerSecond * 60; internal const int MillisPerHour = MillisPerMinute * 60; internal const int MillisPerDay = MillisPerHour * 24; // Number of days in a non-leap year internal const int DaysPerYear = 365; // Number of days in 4 years internal const int DaysPer4Years = DaysPerYear * 4 + 1; // Number of days in 100 years internal const int DaysPer100Years = DaysPer4Years * 25 - 1; // Number of days in 400 years internal const int DaysPer400Years = DaysPer100Years * 4 + 1; // Number of days from 1/1/0001 to 1/1/10000 internal const int DaysTo10000 = DaysPer400Years * 25 - 366; internal const long MaxMillis = (long)DaysTo10000 * MillisPerDay; internal const int DatePartYear = 0; internal const int DatePartDayOfYear = 1; internal const int DatePartMonth = 2; internal const int DatePartDay = 3; // // This is the max Gregorian year can be represented by DateTime class. The limitation // is derived from DateTime class. // internal int MaxYear { get { return (m_maxYear); } } internal static readonly int[] DaysToMonth365 = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }; internal static readonly int[] DaysToMonth366 = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }; [OptionalField(VersionAdded = 1)] internal int m_maxYear = 9999; [OptionalField(VersionAdded = 1)] internal int m_minYear; internal Calendar m_Cal; [OptionalField(VersionAdded = 1)] internal EraInfo[] m_EraInfo; [OptionalField(VersionAdded = 1)] internal int[] m_eras = null; // Construct an instance of gregorian calendar. internal GregorianCalendarHelper(Calendar cal, EraInfo[] eraInfo) { m_Cal = cal; m_EraInfo = eraInfo; m_maxYear = m_EraInfo[0].maxEraYear; m_minYear = m_EraInfo[0].minEraYear; ; } /*=================================GetGregorianYear========================== **Action: Get the Gregorian year value for the specified year in an era. **Returns: The Gregorian year value. **Arguments: ** year the year value in Japanese calendar ** era the Japanese emperor era value. **Exceptions: ** ArgumentOutOfRangeException if year value is invalid or era value is invalid. ============================================================================*/ internal int GetGregorianYear(int year, int era) { if (year < 0) { throw new ArgumentOutOfRangeException(nameof(year), SR.ArgumentOutOfRange_NeedNonNegNum); } Contract.EndContractBlock(); if (era == Calendar.CurrentEra) { era = m_Cal.CurrentEraValue; } for (int i = 0; i < m_EraInfo.Length; i++) { if (era == m_EraInfo[i].era) { if (year < m_EraInfo[i].minEraYear || year > m_EraInfo[i].maxEraYear) { throw new ArgumentOutOfRangeException( nameof(year), String.Format( CultureInfo.CurrentCulture, SR.ArgumentOutOfRange_Range, m_EraInfo[i].minEraYear, m_EraInfo[i].maxEraYear)); } return (m_EraInfo[i].yearOffset + year); } } throw new ArgumentOutOfRangeException(nameof(era), SR.ArgumentOutOfRange_InvalidEraValue); } internal bool IsValidYear(int year, int era) { if (year < 0) { return false; } if (era == Calendar.CurrentEra) { era = m_Cal.CurrentEraValue; } for (int i = 0; i < m_EraInfo.Length; i++) { if (era == m_EraInfo[i].era) { if (year < m_EraInfo[i].minEraYear || year > m_EraInfo[i].maxEraYear) { return false; } return true; } } return false; } // Returns a given date part of this DateTime. This method is used // to compute the year, day-of-year, month, or day part. internal virtual int GetDatePart(long ticks, int part) { CheckTicksRange(ticks); // n = number of days since 1/1/0001 int n = (int)(ticks / TicksPerDay); // y400 = number of whole 400-year periods since 1/1/0001 int y400 = n / DaysPer400Years; // n = day number within 400-year period n -= y400 * DaysPer400Years; // y100 = number of whole 100-year periods within 400-year period int y100 = n / DaysPer100Years; // Last 100-year period has an extra day, so decrement result if 4 if (y100 == 4) y100 = 3; // n = day number within 100-year period n -= y100 * DaysPer100Years; // y4 = number of whole 4-year periods within 100-year period int y4 = n / DaysPer4Years; // n = day number within 4-year period n -= y4 * DaysPer4Years; // y1 = number of whole years within 4-year period int y1 = n / DaysPerYear; // Last year has an extra day, so decrement result if 4 if (y1 == 4) y1 = 3; // If year was requested, compute and return it if (part == DatePartYear) { return (y400 * 400 + y100 * 100 + y4 * 4 + y1 + 1); } // n = day number within year n -= y1 * DaysPerYear; // If day-of-year was requested, return it if (part == DatePartDayOfYear) { return (n + 1); } // Leap year calculation looks different from IsLeapYear since y1, y4, // and y100 are relative to year 1, not year 0 bool leapYear = (y1 == 3 && (y4 != 24 || y100 == 3)); int[] days = leapYear ? DaysToMonth366 : DaysToMonth365; // All months have less than 32 days, so n >> 5 is a good conservative // estimate for the month int m = (n >> 5) + 1; // m = 1-based month number while (n >= days[m]) m++; // If month was requested, return it if (part == DatePartMonth) return (m); // Return 1-based day-of-month return (n - days[m - 1] + 1); } /*=================================GetAbsoluteDate========================== **Action: Gets the absolute date for the given Gregorian date. The absolute date means ** the number of days from January 1st, 1 A.D. **Returns: the absolute date **Arguments: ** year the Gregorian year ** month the Gregorian month ** day the day **Exceptions: ** ArgumentOutOfRangException if year, month, day value is valid. **Note: ** This is an internal method used by DateToTicks() and the calculations of Hijri and Hebrew calendars. ** Number of Days in Prior Years (both common and leap years) + ** Number of Days in Prior Months of Current Year + ** Number of Days in Current Month ** ============================================================================*/ internal static long GetAbsoluteDate(int year, int month, int day) { if (year >= 1 && year <= 9999 && month >= 1 && month <= 12) { int[] days = ((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))) ? DaysToMonth366 : DaysToMonth365; if (day >= 1 && (day <= days[month] - days[month - 1])) { int y = year - 1; int absoluteDate = y * 365 + y / 4 - y / 100 + y / 400 + days[month - 1] + day - 1; return (absoluteDate); } } throw new ArgumentOutOfRangeException(null, SR.ArgumentOutOfRange_BadYearMonthDay); } // Returns the tick count corresponding to the given year, month, and day. // Will check the if the parameters are valid. internal static long DateToTicks(int year, int month, int day) { return (GetAbsoluteDate(year, month, day) * TicksPerDay); } // Return the tick count corresponding to the given hour, minute, second. // Will check the if the parameters are valid. internal static long TimeToTicks(int hour, int minute, int second, int millisecond) { //TimeSpan.TimeToTicks is a family access function which does no error checking, so //we need to put some error checking out here. if (hour >= 0 && hour < 24 && minute >= 0 && minute < 60 && second >= 0 && second < 60) { if (millisecond < 0 || millisecond >= MillisPerSecond) { throw new ArgumentOutOfRangeException( nameof(millisecond), String.Format( CultureInfo.CurrentCulture, SR.ArgumentOutOfRange_Range, 0, MillisPerSecond - 1)); } return (InternalGlobalizationHelper.TimeToTicks(hour, minute, second) + millisecond * TicksPerMillisecond); ; } throw new ArgumentOutOfRangeException(null, SR.ArgumentOutOfRange_BadHourMinuteSecond); } internal void CheckTicksRange(long ticks) { if (ticks < m_Cal.MinSupportedDateTime.Ticks || ticks > m_Cal.MaxSupportedDateTime.Ticks) { throw new ArgumentOutOfRangeException( "time", String.Format( CultureInfo.InvariantCulture, SR.ArgumentOutOfRange_CalendarRange, m_Cal.MinSupportedDateTime, m_Cal.MaxSupportedDateTime)); } Contract.EndContractBlock(); } // 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 DateTime AddMonths(DateTime time, int months) { if (months < -120000 || months > 120000) { throw new ArgumentOutOfRangeException( nameof(months), String.Format( CultureInfo.CurrentCulture, SR.ArgumentOutOfRange_Range, -120000, 120000)); } Contract.EndContractBlock(); CheckTicksRange(time.Ticks); 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[] daysArray = (y % 4 == 0 && (y % 100 != 0 || y % 400 == 0)) ? DaysToMonth366 : DaysToMonth365; int days = (daysArray[m] - daysArray[m - 1]); if (d > days) { d = days; } long ticks = DateToTicks(y, m, d) + (time.Ticks % TicksPerDay); Calendar.CheckAddResult(ticks, m_Cal.MinSupportedDateTime, m_Cal.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 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 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 DayOfWeek GetDayOfWeek(DateTime time) { CheckTicksRange(time.Ticks); return ((DayOfWeek)((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 int GetDayOfYear(DateTime time) { return (GetDatePart(time.Ticks, DatePartDayOfYear)); } // Returns the number of days in the month given by the year and // month arguments. // [Pure] public int GetDaysInMonth(int year, int month, int era) { // // Convert year/era value to Gregorain year value. // year = GetGregorianYear(year, era); if (month < 1 || month > 12) { throw new ArgumentOutOfRangeException(nameof(month), SR.ArgumentOutOfRange_Month); } int[] days = ((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)) ? DaysToMonth366 : DaysToMonth365); return (days[month] - days[month - 1]); } // Returns the number of days in the year given by the year argument for the current era. // public int GetDaysInYear(int year, int era) { // // Convert year/era value to Gregorain year value. // year = GetGregorianYear(year, era); return ((year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)) ? 366 : 365); } // Returns the era for the specified DateTime value. public int GetEra(DateTime time) { long ticks = time.Ticks; // The assumption here is that m_EraInfo is listed in reverse order. for (int i = 0; i < m_EraInfo.Length; i++) { if (ticks >= m_EraInfo[i].ticks) { return (m_EraInfo[i].era); } } throw new ArgumentOutOfRangeException(nameof(time), SR.ArgumentOutOfRange_Era); } public int[] Eras { get { if (m_eras == null) { m_eras = new int[m_EraInfo.Length]; for (int i = 0; i < m_EraInfo.Length; i++) { m_eras[i] = m_EraInfo[i].era; } } return ((int[])m_eras.Clone()); } } // Returns the month part of the specified DateTime. The returned value is an // integer between 1 and 12. // public int GetMonth(DateTime time) { return (GetDatePart(time.Ticks, DatePartMonth)); } // Returns the number of months in the specified year and era. public int GetMonthsInYear(int year, int era) { year = GetGregorianYear(year, era); return (12); } // Returns the year part of the specified DateTime. The returned value is an // integer between 1 and 9999. // public int GetYear(DateTime time) { long ticks = time.Ticks; int year = GetDatePart(ticks, DatePartYear); for (int i = 0; i < m_EraInfo.Length; i++) { if (ticks >= m_EraInfo[i].ticks) { return (year - m_EraInfo[i].yearOffset); } } throw new ArgumentException(SR.Argument_NoEra); } // Returns the year that match the specified Gregorian year. The returned value is an // integer between 1 and 9999. // public int GetYear(int year, DateTime time) { long ticks = time.Ticks; for (int i = 0; i < m_EraInfo.Length; i++) { // while calculating dates with JapaneseLuniSolarCalendar, we can run into cases right after the start of the era // and still belong to the month which is started in previous era. Calculating equivalent calendar date will cause // using the new era info which will have the year offset equal to the year we are calculating year = m_EraInfo[i].yearOffset // which will end up with zero as calendar year. // We should use the previous era info instead to get the right year number. Example of such date is Feb 2nd 1989 if (ticks >= m_EraInfo[i].ticks && year > m_EraInfo[i].yearOffset) { return (year - m_EraInfo[i].yearOffset); } } throw new ArgumentException(SR.Argument_NoEra); } // 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 bool IsLeapDay(int year, int month, int day, int era) { // year/month/era checking is done in GetDaysInMonth() if (day < 1 || day > GetDaysInMonth(year, month, era)) { throw new ArgumentOutOfRangeException( nameof(day), String.Format( CultureInfo.CurrentCulture, SR.ArgumentOutOfRange_Range, 1, GetDaysInMonth(year, month, era))); } Contract.EndContractBlock(); if (!IsLeapYear(year, era)) { return (false); } if (month == 2 && day == 29) { return (true); } return (false); } // 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 int GetLeapMonth(int year, int era) { year = GetGregorianYear(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 bool IsLeapMonth(int year, int month, int era) { year = GetGregorianYear(year, era); if (month < 1 || month > 12) { throw new ArgumentOutOfRangeException( nameof(month), String.Format( CultureInfo.CurrentCulture, SR.ArgumentOutOfRange_Range, 1, 12)); } 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 bool IsLeapYear(int year, int era) { year = GetGregorianYear(year, era); return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); } // Returns the date and time converted to a DateTime value. Throws an exception if the n-tuple is invalid. // public DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era) { year = GetGregorianYear(year, era); long ticks = DateToTicks(year, month, day) + TimeToTicks(hour, minute, second, millisecond); CheckTicksRange(ticks); return (new DateTime(ticks)); } public virtual int GetWeekOfYear(DateTime time, CalendarWeekRule rule, DayOfWeek firstDayOfWeek) { CheckTicksRange(time.Ticks); // Use GregorianCalendar to get around the problem that the implmentation in Calendar.GetWeekOfYear() // can call GetYear() that exceeds the supported range of the Gregorian-based calendars. return (GregorianCalendar.GetDefaultInstance().GetWeekOfYear(time, rule, firstDayOfWeek)); } public int ToFourDigitYear(int year, int twoDigitYearMax) { if (year < 0) { throw new ArgumentOutOfRangeException(nameof(year), SR.ArgumentOutOfRange_NeedPosNum); } Contract.EndContractBlock(); if (year < 100) { int y = year % 100; return ((twoDigitYearMax / 100 - (y > twoDigitYearMax % 100 ? 1 : 0)) * 100 + y); } if (year < m_minYear || year > m_maxYear) { throw new ArgumentOutOfRangeException( nameof(year), String.Format( CultureInfo.CurrentCulture, SR.ArgumentOutOfRange_Range, m_minYear, m_maxYear)); } // If the year value is above 100, just return the year value. Don't have to do // the TwoDigitYearMax comparison. return (year); } } }