internal virtual int GetDatePart(long ticks, int part) {
// The Gregorian year, month, day value for ticks.
int gregorianYear, gregorianMonth, gregorianDay;
int hebrewYearType; // lunar year type
long AbsoluteDate; // absolute date - absolute date 1/1/1600
//
// Make sure we have a valid Gregorian date that will fit into our
// Hebrew conversion limits.
//
CheckTicksRange(ticks);
DateTime time = new DateTime(ticks);
//
// Save the Gregorian date values.
//
gregorianYear = time.Year;
gregorianMonth = time.Month;
gregorianDay = time.Day;
__DateBuffer lunarDate = new __DateBuffer(); // lunar month and day for Jan 1
// From the table looking-up value of m_HebrewTable[index] (stored in lunarDate.day), we get the the
// lunar month and lunar day where the Gregorian date 1/1 falls.
lunarDate.year = gregorianYear + HebrewYearOf1AD;
hebrewYearType = GetLunarMonthDay(gregorianYear, lunarDate);
// This is the buffer used to store the result Hebrew date.
__DateBuffer result = new __DateBuffer();
//
// Store the values for the start of the new year - 1/1.
//
result.year = lunarDate.year;
result.month = lunarDate.month;
result.day = lunarDate.day;
//
// Get the absolute date from 1/1/1600.
//
AbsoluteDate = GregorianCalendar.GetAbsoluteDate(gregorianYear, gregorianMonth, gregorianDay);
//
// If the requested date was 1/1, then we're done.
//
if ((gregorianMonth == 1) && (gregorianDay == 1)) {
return (GetResult(result, part));
}
//
// Calculate the number of days between 1/1 and the requested date.
//
long NumDays; // number of days since 1/1
NumDays = AbsoluteDate - GregorianCalendar.GetAbsoluteDate(gregorianYear, 1, 1);
//
// If the requested date is within the current lunar month, then
// we're done.
//
if ((NumDays + (long)lunarDate.day) <= (long)(m_lunarMonthLen[hebrewYearType, lunarDate.month])) {
result.day += (int)NumDays;
return (GetResult(result, part));
}
//
// Adjust for the current partial month.
//
result.month++;
result.day = 1;
//
// Adjust the Lunar Month and Year (if necessary) based on the number
// of days between 1/1 and the requested date.
//
// Assumes Jan 1 can never translate to the last Lunar month, which
// is true.
//
NumDays -= (long)(m_lunarMonthLen[hebrewYearType, lunarDate.month] - lunarDate.day);
BCLDebug.Assert(NumDays >= 1, "NumDays >= 1");
// If NumDays is 1, then we are done. Otherwise, find the correct Hebrew month
// and day.
if (NumDays > 1) {
//
// See if we're on the correct Lunar month.
//
while (NumDays > (long)(m_lunarMonthLen[hebrewYearType, result.month])) {
//
// Adjust the number of days and move to the next month.
//
NumDays -= (long)(m_lunarMonthLen[hebrewYearType, result.month++]);
//
// See if we need to adjust the Year.
// Must handle both 12 and 13 month years.
//
if ((result.month > 13) || (m_lunarMonthLen[hebrewYearType, result.month] == 0)) {
//
// Adjust the Year.
//
result.year++;
hebrewYearType = m_HebrewTable[(gregorianYear + 1 - FirstGregorianTableYear) * 2 + 1];
//
// Adjust the Month.
//
result.month = 1;
}
}
//
// Found the right Lunar month.
//
result.day += (int)(NumDays - 1);
}
return (GetResult(result, part));
}
