if(input.Start_Date != null && input.Frequency != null)
{
	mon = input.Frequency;
	input.Cal_Due_Date = input.Start_Date.addDay(mon);
	input.Cal_Due_Date = input.Cal_Due_Date.subDay(1);
	startDate = input.Cal_Due_Date;
	endDate = input.Today.subDay(1);
	input.Days_Left = daysBetween(endDate,startDate);
}