Way to use c# datetime.

When you want to get number of days according to given date,
you can use this function in c# .net

public int getNumberOfDayByGivenDate(DateTime dtGivenDate)
{
DateTime dtMyDate = DateTime.Parse("16/10/2009");
TimeSpan tsGetNumber = dtGivenDate.Subtract(dtMyDate);
return tsGetNumber.Days;
}

When you want to get date format data according to given integer number,
you can use below function in c# .net

public DateTime getDateByGivenNumber(int GivenNumber)
{
DateTime dtMyDate = DateTime.Parse("16/10/2009");
TimeSpan tsByGivenNumber = new TimeSpan(GivenNumber, 0, 0, 0);
return dtMyDate.Add(tsByGivenNumber);
}