I am happy to report that you can resize periods based on duration. By default, all periods appear to have the same size in the view regardless of their actual duration. Choose ‘Owl > Help > Options’, expand ‘Advanced options’ and check ‘Resize periods based on duration’ if you want to change this behavior, e.g. you want to see a 15-minute period proportionally smaller compared to a 45-minute period. The same option is available when publishing timetable to the web, so you can fully control how the timetable will be displayed to others. Thank you all, for adding suggestion for improvement and voting for it!

Best regards,
Danijel Stulic, co-founder of Prime Timetable