Calendar: show 15 minutes grid lines

[martintaal]

Hi,
I can force the calendar to snapgap on 15 minutes intervals. The lines of the calendar are shown at 30 minute intervals however.

Is it somehow possible to show the grid lines at 15 minutes intervals?
Is this a configurable setting?

gr. Martin

[Isomorphic]

Unfortunately not - vertical calendars are currently tied to 30 minute row heights