public DateTime ExpirationDate(int year, int month, string countryCode = "US")
{
var referenceDay = new DateTime(year, month, 1);
var calendar = MyUtils.GetCalendarFromCountryCode(countryCode);
int day;
referenceDay = referenceDay.AddMonths((int)Rule.ReferenceRelativeMonth);
if (Rule.ReferenceDayIsLastBusinessDayOfMonth)
{
var tmpDay = referenceDay.AddMonths(1).AddDays(-1);
while (!calendar.isBusinessDay(tmpDay))
{
tmpDay = tmpDay.AddDays(-1);
}
day = tmpDay.Day;
}
else if (Rule.ReferenceUsesDays) // we use a fixed number of days from the start of the month
{
day = Rule.ReferenceDays;
}
else // we use a number of weeks and then a weekday of that week
{
if (Rule.ReferenceWeekDayCount == WeekDayCount.Last) //the last week of the month
{
var tmpDay = referenceDay.AddMonths(1).AddDays(-1);
while (tmpDay.DayOfWeek.ToInt() != (int)Rule.ReferenceWeekDay)
{
tmpDay = tmpDay.AddDays(-1);
}
day = tmpDay.Day;
}
else // 1st to 4th week of the month, just loop until we find the right day
{
var weekCount = 0;
while (weekCount < (int)Rule.ReferenceWeekDayCount + 1)
{
if (referenceDay.DayOfWeek.ToInt() == (int)Rule.ReferenceWeekDay)
{
weekCount++;
}
referenceDay = referenceDay.AddDays(1);
}
day = referenceDay.Day - 1;
}
}
referenceDay = new DateTime(year, month, day).AddMonths((int)Rule.ReferenceRelativeMonth);
if (Rule.ReferenceDayMustBeBusinessDay)
{
while (!calendar.isBusinessDay(referenceDay))
{
referenceDay = referenceDay.AddDays(-1);
}
}
switch (Rule.DayType)
{
case DayType.Business:
var daysLeft = Rule.DaysBefore;
var daysBack = 0;
while (daysLeft > 0)
{
daysBack++;
if (calendar.isBusinessDay(referenceDay.AddDays(-daysBack)))
{
daysLeft--;
}
}
return(referenceDay.AddDays(-daysBack));
case DayType.Calendar:
return(referenceDay.AddDays(-Rule.DaysBefore));
default:
return(referenceDay);
}
}