offsetForDateTime method
Implementation
double offsetForDateTime(DateTime dateTime) {
final int year = dateTime.year;
if (!_yearOffsetCache.containsKey(year)) {
calculateYearOffsets();
}
double ret = _yearOffsetCache[year] ?? 0.0;
final XBCalendarYear? calendarYear = years[year];
if (calendarYear != null) {
ret += calendarYear.offset(dateTime.month);
}
return ret;
}