I am trying to show 24 hour format using this line:
Text='<%# Bind("Appointment", "{HH:mm}")
So how will it be created to show, for example, 16:40 instead of 4:40?
if you don't need to link it try:
Text = '<% # string.Format ("{0: HH: mm}", Eval ("Destination"))%>'
Otherwise, suppose you can update the field value in the OnDataBound event.