Week Of Year

c#에서 Week Of Year 값 구하기

GregorianCalendar cal = new GregorianCalendar(GregorianCalendarTypes.Localized);
int week = cal.GetWeekOfYear(date, CalendarWeekRule.FirstFullWeek, firstDayOfWeek);

if(date.Month == 1 && week >= 50)
{
	return date.AddYears(-1).Year.ToString() + week.ToString().PadLeft(2, '0');
}
else
{
	return date.Year.ToString() + week.ToString().PadLeft(2, '0');
}