With JavaScript :
calculating-the-difference-between-two-dates-in-javascript.html[
^]
With C#:
private void CalculateDateDifference()
{
TimeSpan i = new TimeSpan(0, 0, 0);
DateTime startDate = Convert.ToDateTime(this.txtStartDate.Text.Trim(), new CultureInfo("en-us"));
DateTime endDate = Convert.ToDateTime(this.txtEndDate.Text.Trim(), new CultureInfo("en-us"));
i += endDate.Subtract(startDate);
int days = i.Days;
this.lblDays.Text = "Total Days : " + days.ToString();
}
-KR