blackberry calendar
 

simple question and hopefully a simple solution: How do i get the calendar to have appointments every half hour rather than every hour in the day view set as default?

You cant. But you can easily create an appointment on :15 :30 :45 markers.
1. Start typing the appointment in an adjacent hour
2. Hold ALT (moon key) and spin the scrollwheel to change between :00 :15 :30 :45

No need to open the appointment to edit it. It can all be directly done in the standard calendar day view.

More information in BlackBerry Calendar Tricks.

Problem solved! (hopefully)

Chk the app
 

That should be a function of whatever calendaring application your BB is syncing with.