When I create a new calendar event on my Nokia N9, I can set the duration to 0, 15, 30 minutes, 1, 2 hours, All day or Custom.

I find that a lot of my events are typically 3-5 hours, and would like to add 3, 4 , 5 hours to the list, so I don't have to go through all the taps required when I choose Custom.

I guess there is a file I can edit to achieve this. Anyone knows?