Academic Settings / Timetable / Timetable Settings / Timetable Creation Settings / Timetable calendar time slot (for calendar view option)
Here you should define the number of minutes used to split the timetable calendar. E.g. if you define 30 then the timetable calendar view will be split into 30 minutes rows (e.g. 09.00,09.30, 10.00 etc.). If you write here 60 then the split will be per hour (09.00, 10.00, 11.00 etc.). If you need to have classes starting only on exact hours, then use 60. If you need your classes to start at any time such as 09.15 then enter 15. The smallest the number the most zoomed in is the calendar and the longest the calendar view will be.
Setting -> Active -> 45
Figure 1
Setting -> Inactive -> Default Value is per hour
Figure 2
