In Online Booking it is possible to set the time limits to set up the minimum and maximum rental periods permitted as well as the minimum time a reservation can be placed in advanced (lead time).
However you might want use different settings for each Product Family. You don't want your high end road bike to be rented for less than 3 hours, and you e-bike not longer then eight hour to prevent empty batteries.
This setting is part of Online Booking buffers, so you should enable that feature first (no need to actually use that).
Enable the feature in Settings - Features and Customization: toggle the switch and click Save.
Now you can set Minimum and Maximum Durations in the desired Product Family. This will override the main setting in Online booking Time Limits.
If you use multiple product families it is even easier to set the Min/Max durations in Settings - Product Compatibility
Also see: Booking Buffers in Online Booking