I have answered to your question in the support ticket you have sent.
For your convenience the answer to your question cold also be found here.
In respect to your question:
I have made an example for you showing how appointments could be added server-side.
I have used a button that makes a post-back to the server and in its OnClick event handler I add appointments to the scheduler.
Here is the example:
Protected Sub Button1_Click(sender As [Object], args As EventArgs)
For counter As Integer = 1 To 3
Dim start As DateTime = DateTime.Now.ToUniversalTime()
start = start.AddHours(counter)
Dim [end] As DateTime = start.AddHours(1)
Dim apt As New Appointment(counter.ToString(), start, [end], "Subject of appointmenrt_" & counter.ToString())
I hope this would help you.
the Telerik team