How to disable past/previous dates in Calendar Control in ASP.Net?

You have to implement some logic in DayRender event of calendar control so that it disables the past dates. Try the code as follows:

protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
    if (e.Day.Date.CompareTo(DateTime.Today) < 0)
    {
        e.Day.IsSelectable = false;
    }
}

Sometimes searching a solution is easier & faster than asking questions. :)

- DD