private DateTime FindPrevRelevantDate(DateTime datetime)
{
var relevantDateTime = new DateTime();
day = datetime.Day;
month = datetime.Month;
year = datetime.Year;
var minDay = Days.Min();
var minMonth = Months.Min();
var minYear = Years.Min();
var minDate = new DateTime(minYear, minMonth, minDay).Date;
bool subtracted = false;
while (datetime.Date != minDate)
{
if (DaysOfWeek.Contains((int)datetime.DayOfWeek))
{
relevantDateTime = datetime;
break;
}
else
{
subtracted = false;
}
SubtractNext(Days, ref day, ref subtracted);
var monthSubtracted = SubtractNext(Months, ref month, ref subtracted);
if (monthSubtracted)
{
day = GetClosestDay(datetime, year, month);
}
SubtractNext(Years, ref year, ref subtracted);
datetime = new DateTime(year, month, day,
datetime.Hour, datetime.Minute, datetime.Second, datetime.Millisecond);
}
return(relevantDateTime);
}
