PersianCalendar.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / whidbey / netfxsp / ndp / clr / src / BCL / System / Globalization / PersianCalendar.cs / 1 / PersianCalendar.cs

                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
namespace System.Globalization {
    using System; 
 
    ////////////////////////////////////////////////////////////////////////////
    // 
    //  Notes about PersianCalendar
    //
    ////////////////////////////////////////////////////////////////////////////
     /* 
     **  Calendar support range:
     **      Calendar    Minimum     Maximum 
     **      ==========  ==========  ========== 
     **      Gregorian   0622/03/21   9999/12/31
     **      Persian     0001/01/01   9378/10/10 
     */

    [Serializable]
    public class PersianCalendar : Calendar { 

 
        public static readonly int PersianEra = 1; 

        internal const int DateCycle = 33; 
        internal const int DatePartYear = 0;
        internal const int DatePartDayOfYear = 1;
        internal const int DatePartMonth = 2;
        internal const int DatePartDay = 3; 

        internal static int[] DaysToMonth = {0,31,62,93,124,155,186,216,246,276,306,336}; 
        //Leap years, if Y%33 is 1,5,9,13,17,22,26,30 
        internal static int[] LeapYears33 = {0,1,0,0,0,  //  0  [1]  2   3   4
                                             1,0,0,0,1,  // [5]  6   7   8  [9] 
                                             0,0,0,1,0,  // 10  11  12 [13] 14
                                             0,0,1,0,0,  // 15  16 [17] 18  19
                                             0,0,1,0,0,     // 20  21 [22] 23  24
                                             0,1,0,0,0,  // 25 [26] 27  28  29 
                                             1,0,0};     //[30] 31  32
 
        internal const int LeapYearsPerCycle = 8; 
        internal const long GregorianOffset = 226894; //GregorianCalendar.GetAbsoluteDate(622, 3, 21);
        internal const long DaysPerCycle = DateCycle * 365 + LeapYearsPerCycle; 

        //internal static Calendar m_defaultInstance;

        // DateTime.MaxValue = Persian calendar (year:9378, month: 10, day: 10). 
        internal const int MaxCalendarYear = 9378;
        internal const int MaxCalendarMonth = 10; 
        internal const int MaxCalendarDay = 10; 
        // Persian calendar (year: 1, month: 1, day:1 ) = Gregorian (year: 622, month: 3, day: 21)
        // This is the minimal Gregorian date that we support in the PersianCalendar. 
        internal static DateTime minDate = new DateTime(622, 3, 21);
        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) 
            {
                return DaysUpToPersianYear(year) + DaysToMonth[month-1] + day - 1; 
            } 
            throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay"));
        } 

        /*=================================DaysUpToPersianYear==========================
        **Action: Gets the total number of days (absolute date) up to the given Persian Year.
        **       The absolute date means the number of days from January 1st, 1 A.D. 
        **Returns: Gets the total number of days (absolute date) up to the given Persian Year.
        **Arguments: PersianYear year value in Persian calendar. 
        **Exceptions: None 
        **Notes:
        ============================================================================*/ 

        long DaysUpToPersianYear(int PersianYear) {

            long NumDays;          // number of absolute days 
            int NumCycles;         // number of 33 year cycles
            int NumYearsLeft;      // number of years into 33 year cycle 
 
            //
            //  Compute the number of 33 years cycles. 
            //
            NumCycles = (PersianYear - 1) / DateCycle;

            // 
            //  Compute the number of years left.  This is the number of years
            //  into the 33 year cycle for the given year. 
            // 
            NumYearsLeft = (PersianYear-1) % DateCycle;
 
            //
            //  Compute the number of absolute days up to the given year.
            //
            NumDays = NumCycles * DaysPerCycle + GregorianOffset; 
            while (NumYearsLeft > 0) {
                NumDays += 365; 
                // Common year is 365 days, and leap year is 366 days. 
                if(IsLeapYear(NumYearsLeft, CurrentEra)) {
                    NumDays++; 
                }
                NumYearsLeft--;
            }
 
            //
            //  Return the number of absolute days. 
            // 
            return (NumDays);
        } 


        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));
            }
        } 

        internal void CheckEraRange(int era) { 
            if (era != CurrentEra && era != PersianEra) { 
                throw new ArgumentOutOfRangeException("era", Environment.GetResourceString("ArgumentOutOfRange_InvalidEraValue"));
            } 
        }

        internal void CheckYearRange(int year, int era) {
            CheckEraRange(era); 
            if (year < 1 || year > MaxCalendarYear) {
                throw new ArgumentOutOfRangeException( 
                            "year", 
                            String.Format(
                                CultureInfo.CurrentCulture, 
                                Environment.GetResourceString("ArgumentOutOfRange_Range"),
                                1,
                                MaxCalendarYear));
            } 
        }
 
        internal void CheckYearMonthRange(int year, int month, int era) { 
            CheckYearRange(year, era);
            if (year == MaxCalendarYear) { 
                if (month > MaxCalendarMonth) {
                    throw new ArgumentOutOfRangeException(
                                "month",
                                String.Format( 
                                    CultureInfo.CurrentCulture,
                                    Environment.GetResourceString("ArgumentOutOfRange_Range"), 
                                    1, 
                                    MaxCalendarMonth));
                } 
            }

            if (month < 1 || month > 12) {
                throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_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. 
        **Notes:
        **      First, we get the absolute date (the number of days from January 1st, 1 A.C) for the given ticks. 
        **      Use the formula (((AbsoluteDate - 226894) * 33) / (33 * 365 + 8)) + 1, we can a rough value for the Persian year. 
        **      In order to get the exact Persian year, we compare the exact absolute date for PersianYear and (PersianYear + 1).
        **      From here, we can get the correct Persian year. 
        ============================================================================*/

        internal int GetDatePart(long ticks, int part) {
            int PersianYear;              // Persian year 
            int PersianMonth;             // Persian month
            int PersianDay;               // Persian day 
            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 from this magic formula.
            //
            PersianYear = (int)(((NumDays - GregorianOffset) * DateCycle) / DaysPerCycle) + 1;
 
            long daysToPersianYear = DaysUpToPersianYear(PersianYear);          // The absoulte date for PersianYear
            long daysOfPersianYear = GetDaysInYear(PersianYear, CurrentEra);    // The number of days for (PersianYear+1) year. 
 
            if (NumDays < daysToPersianYear) {
                daysToPersianYear -= daysOfPersianYear; 
                PersianYear--;
            } else if (NumDays == daysToPersianYear) {
                PersianYear--;
                daysToPersianYear -= GetDaysInYear(PersianYear, CurrentEra); 
            } else {
                if (NumDays > daysToPersianYear + daysOfPersianYear) { 
                    daysToPersianYear += daysOfPersianYear; 
                    PersianYear++;
                } 
            }
            if (part == DatePartYear) {
                return (PersianYear);
            } 

            // 
            //  Calculate the Persian Month. 
            //
 
            NumDays -= daysToPersianYear;

            if (part == DatePartDayOfYear) {
                return ((int)NumDays); 
            }
 
            PersianMonth = 0; 
            while ((PersianMonth < 12) && (NumDays > DaysToMonth[PersianMonth]))
            { 
                PersianMonth++;
            }

            if (part == DatePartMonth) { 
                return (PersianMonth);
            } 
 
            //
            //  Calculate the Persian Day. 
            //
            PersianDay = (int)(NumDays - DaysToMonth[PersianMonth-1]);

            if (part == DatePartDay) { 
                return (PersianDay);
            } 
            // 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(
                            "months", 
                            String.Format( 
                                CultureInfo.CurrentCulture,
                                Environment.GetResourceString("ArgumentOutOfRange_Range"), 
                                -120000,
                                120000));
            }
            // 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;
            } 
 
            if (month == 12) {
                // For the 12th month, leap year has 30 days, and common year has 29 days. 
                return (IsLeapYear(year, CurrentEra) ? 30 : 29);
            }
            // Other months first 6 months are 31 and the reset are 30 days.
            return ((month > 6) ? 30 : 31); 
        }
 
        // 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(
                            "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); 
            return (LeapYears33[year%DateCycle]==1);
        } 
 
        // 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(
                            "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(
                                "value", 
                                String.Format( 
                                    CultureInfo.CurrentCulture,
                                    Environment.GetResourceString("ArgumentOutOfRange_Range"), 
                                    99,
                                    MaxCalendarYear));
                }
                twoDigitYearMax = value; 
            }
        } 
 

 
        public override int ToFourDigitYear(int year) {
            if (year < 100) {
                return (base.ToFourDigitYear(year));
            } 

            if (year > MaxCalendarYear) { 
                throw new ArgumentOutOfRangeException( 
                            "year",
                            String.Format( 
                                CultureInfo.CurrentCulture,
                                Environment.GetResourceString("ArgumentOutOfRange_Range"),
                                1,
                                MaxCalendarYear)); 
            }
            return (year); 
        } 
    }
} 



 

 
 

 



 

 
 

 



 

 
 

 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
namespace System.Globalization {
    using System; 
 
    ////////////////////////////////////////////////////////////////////////////
    // 
    //  Notes about PersianCalendar
    //
    ////////////////////////////////////////////////////////////////////////////
     /* 
     **  Calendar support range:
     **      Calendar    Minimum     Maximum 
     **      ==========  ==========  ========== 
     **      Gregorian   0622/03/21   9999/12/31
     **      Persian     0001/01/01   9378/10/10 
     */

    [Serializable]
    public class PersianCalendar : Calendar { 

 
        public static readonly int PersianEra = 1; 

        internal const int DateCycle = 33; 
        internal const int DatePartYear = 0;
        internal const int DatePartDayOfYear = 1;
        internal const int DatePartMonth = 2;
        internal const int DatePartDay = 3; 

        internal static int[] DaysToMonth = {0,31,62,93,124,155,186,216,246,276,306,336}; 
        //Leap years, if Y%33 is 1,5,9,13,17,22,26,30 
        internal static int[] LeapYears33 = {0,1,0,0,0,  //  0  [1]  2   3   4
                                             1,0,0,0,1,  // [5]  6   7   8  [9] 
                                             0,0,0,1,0,  // 10  11  12 [13] 14
                                             0,0,1,0,0,  // 15  16 [17] 18  19
                                             0,0,1,0,0,     // 20  21 [22] 23  24
                                             0,1,0,0,0,  // 25 [26] 27  28  29 
                                             1,0,0};     //[30] 31  32
 
        internal const int LeapYearsPerCycle = 8; 
        internal const long GregorianOffset = 226894; //GregorianCalendar.GetAbsoluteDate(622, 3, 21);
        internal const long DaysPerCycle = DateCycle * 365 + LeapYearsPerCycle; 

        //internal static Calendar m_defaultInstance;

        // DateTime.MaxValue = Persian calendar (year:9378, month: 10, day: 10). 
        internal const int MaxCalendarYear = 9378;
        internal const int MaxCalendarMonth = 10; 
        internal const int MaxCalendarDay = 10; 
        // Persian calendar (year: 1, month: 1, day:1 ) = Gregorian (year: 622, month: 3, day: 21)
        // This is the minimal Gregorian date that we support in the PersianCalendar. 
        internal static DateTime minDate = new DateTime(622, 3, 21);
        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) 
            {
                return DaysUpToPersianYear(year) + DaysToMonth[month-1] + day - 1; 
            } 
            throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay"));
        } 

        /*=================================DaysUpToPersianYear==========================
        **Action: Gets the total number of days (absolute date) up to the given Persian Year.
        **       The absolute date means the number of days from January 1st, 1 A.D. 
        **Returns: Gets the total number of days (absolute date) up to the given Persian Year.
        **Arguments: PersianYear year value in Persian calendar. 
        **Exceptions: None 
        **Notes:
        ============================================================================*/ 

        long DaysUpToPersianYear(int PersianYear) {

            long NumDays;          // number of absolute days 
            int NumCycles;         // number of 33 year cycles
            int NumYearsLeft;      // number of years into 33 year cycle 
 
            //
            //  Compute the number of 33 years cycles. 
            //
            NumCycles = (PersianYear - 1) / DateCycle;

            // 
            //  Compute the number of years left.  This is the number of years
            //  into the 33 year cycle for the given year. 
            // 
            NumYearsLeft = (PersianYear-1) % DateCycle;
 
            //
            //  Compute the number of absolute days up to the given year.
            //
            NumDays = NumCycles * DaysPerCycle + GregorianOffset; 
            while (NumYearsLeft > 0) {
                NumDays += 365; 
                // Common year is 365 days, and leap year is 366 days. 
                if(IsLeapYear(NumYearsLeft, CurrentEra)) {
                    NumDays++; 
                }
                NumYearsLeft--;
            }
 
            //
            //  Return the number of absolute days. 
            // 
            return (NumDays);
        } 


        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));
            }
        } 

        internal void CheckEraRange(int era) { 
            if (era != CurrentEra && era != PersianEra) { 
                throw new ArgumentOutOfRangeException("era", Environment.GetResourceString("ArgumentOutOfRange_InvalidEraValue"));
            } 
        }

        internal void CheckYearRange(int year, int era) {
            CheckEraRange(era); 
            if (year < 1 || year > MaxCalendarYear) {
                throw new ArgumentOutOfRangeException( 
                            "year", 
                            String.Format(
                                CultureInfo.CurrentCulture, 
                                Environment.GetResourceString("ArgumentOutOfRange_Range"),
                                1,
                                MaxCalendarYear));
            } 
        }
 
        internal void CheckYearMonthRange(int year, int month, int era) { 
            CheckYearRange(year, era);
            if (year == MaxCalendarYear) { 
                if (month > MaxCalendarMonth) {
                    throw new ArgumentOutOfRangeException(
                                "month",
                                String.Format( 
                                    CultureInfo.CurrentCulture,
                                    Environment.GetResourceString("ArgumentOutOfRange_Range"), 
                                    1, 
                                    MaxCalendarMonth));
                } 
            }

            if (month < 1 || month > 12) {
                throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_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. 
        **Notes:
        **      First, we get the absolute date (the number of days from January 1st, 1 A.C) for the given ticks. 
        **      Use the formula (((AbsoluteDate - 226894) * 33) / (33 * 365 + 8)) + 1, we can a rough value for the Persian year. 
        **      In order to get the exact Persian year, we compare the exact absolute date for PersianYear and (PersianYear + 1).
        **      From here, we can get the correct Persian year. 
        ============================================================================*/

        internal int GetDatePart(long ticks, int part) {
            int PersianYear;              // Persian year 
            int PersianMonth;             // Persian month
            int PersianDay;               // Persian day 
            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 from this magic formula.
            //
            PersianYear = (int)(((NumDays - GregorianOffset) * DateCycle) / DaysPerCycle) + 1;
 
            long daysToPersianYear = DaysUpToPersianYear(PersianYear);          // The absoulte date for PersianYear
            long daysOfPersianYear = GetDaysInYear(PersianYear, CurrentEra);    // The number of days for (PersianYear+1) year. 
 
            if (NumDays < daysToPersianYear) {
                daysToPersianYear -= daysOfPersianYear; 
                PersianYear--;
            } else if (NumDays == daysToPersianYear) {
                PersianYear--;
                daysToPersianYear -= GetDaysInYear(PersianYear, CurrentEra); 
            } else {
                if (NumDays > daysToPersianYear + daysOfPersianYear) { 
                    daysToPersianYear += daysOfPersianYear; 
                    PersianYear++;
                } 
            }
            if (part == DatePartYear) {
                return (PersianYear);
            } 

            // 
            //  Calculate the Persian Month. 
            //
 
            NumDays -= daysToPersianYear;

            if (part == DatePartDayOfYear) {
                return ((int)NumDays); 
            }
 
            PersianMonth = 0; 
            while ((PersianMonth < 12) && (NumDays > DaysToMonth[PersianMonth]))
            { 
                PersianMonth++;
            }

            if (part == DatePartMonth) { 
                return (PersianMonth);
            } 
 
            //
            //  Calculate the Persian Day. 
            //
            PersianDay = (int)(NumDays - DaysToMonth[PersianMonth-1]);

            if (part == DatePartDay) { 
                return (PersianDay);
            } 
            // 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(
                            "months", 
                            String.Format( 
                                CultureInfo.CurrentCulture,
                                Environment.GetResourceString("ArgumentOutOfRange_Range"), 
                                -120000,
                                120000));
            }
            // 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;
            } 
 
            if (month == 12) {
                // For the 12th month, leap year has 30 days, and common year has 29 days. 
                return (IsLeapYear(year, CurrentEra) ? 30 : 29);
            }
            // Other months first 6 months are 31 and the reset are 30 days.
            return ((month > 6) ? 30 : 31); 
        }
 
        // 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(
                            "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); 
            return (LeapYears33[year%DateCycle]==1);
        } 
 
        // 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(
                            "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(
                                "value", 
                                String.Format( 
                                    CultureInfo.CurrentCulture,
                                    Environment.GetResourceString("ArgumentOutOfRange_Range"), 
                                    99,
                                    MaxCalendarYear));
                }
                twoDigitYearMax = value; 
            }
        } 
 

 
        public override int ToFourDigitYear(int year) {
            if (year < 100) {
                return (base.ToFourDigitYear(year));
            } 

            if (year > MaxCalendarYear) { 
                throw new ArgumentOutOfRangeException( 
                            "year",
                            String.Format( 
                                CultureInfo.CurrentCulture,
                                Environment.GetResourceString("ArgumentOutOfRange_Range"),
                                1,
                                MaxCalendarYear)); 
            }
            return (year); 
        } 
    }
} 



 

 
 

 



 

 
 

 



 

 
 

 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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