If you want to do it using ASP.NET (server-side) code then you might want to look at the DateTime.DayOfWeek property of the DateTime instance.
What you would do, is to send the DateTime that the user selected, and on the server side, check the Day for that DateTime as
if(dateTime1.DayOfWeek == DayOfWeek.Monday) {
} else {
}
You can then fill the remaining Controls by the data depending on this. More on
DateTime.DayOfWeek here on MSDN[
^].