By default, the Forms in Coupon Reach's Opening time is 8 AM and the Closing time would is 5 PM.
To edit these, you can go to your Forms, then edit the form of your choice.
Then go to Step 2 (Properties) and click the Reservation Time field element to open it up and edit it. (In the Default form, it says "Around what time?")
Then you'll see the window where you can edit the opening time and close time that the form would follow