Ability for clients to book at anytime in 15 minute increments

I was wondering if it would be possible if something like this is implemented please, as I have seen it used on other software like Fresha and Treatwell. For example, if a client wants to book a 60 min appointment online, and if I start my day on the hour (8/9am etc), then they can only book on the hour too, not at say 9:15, 9:30 or 9:45am. I think this would be really beneficial if possible please. Thank you