calendar default

How do I change the default scheduling for 30 minutes on the calendar to 60
minutes? (Not for display, but for scheduling.) For example, I want to
start a meeting at 8:00 AM, it defaults to 8:30 AM as the end time. I want
to change it so it always defaults an hour in the future. (To 9:00 AM in
this example). Obviously I can change the time manually, but why do that if
there's a way around it? Thanks.