This is a part of an article serie where we create a ASP.NET 2.0 server control providing date (and time) selection popup . Please start from the beginning.
So lets start from the other side. How is the control used:
I have implemented some basic designtime support - pretty much you are able to decide where the control should be located. But - there shouldn't be much more to it.

However, there are properties you can set:

You can also set the properties from the codebehind - of course:
cal1.SingleClick = CheckBox2.Checked;
if (CheckBox3.Checked)
cal1.DateTimeValue = DateTime.Now.AddDays(-7);
cal1.OutputFormat_NET = ddlFormatSamples.SelectedValue;
cal1.ShowWeekNumber = CheckBox4.Checked;