You can cancel your request 3 hours before starting without any fee, after 3 hours and less than 3 hours full amount be calculated as cancelation fee. 

For hourly request you can cancel the ride more than 24 hours before ride schedule without penalty or any cancelation fee. so you have time to cancel the ride 24 hours before starting and after that or less than 24 hours full amount should be pay. 

When you are selecting date, time and address in same page should be click on hourly and confirm how many hours you need.