Question

I have an ASP.NET Calendar control on my web form.

I have defined a date range with a StartDate and an EndDate and now I need to make all the days in between (including the StartDate and EndDate) red.

How I can do this?

Answer 1

You can handle the Calendar.DayRender event and customize the appearance of the cells within your date range. A complete example is on the MSDN documentation page, but the most important part is:

Sub DayRender(source As Object, e As DayRenderEventArgs)
    ' Change the background color of the days in the month to yellow.
    If Not e.Day.IsOtherMonth And Not e.Day.IsWeekend Then
        e.Cell.BackColor = System.Drawing.Color.Yellow
    End If 
End Sub 'DayRender 

You just need to adapt the If to compare the day to your custom range and change the background color from yellow to red.