I am creating a office search for my company, where admin can add the different offices' open and close times. Now when a user try to make a booking, and they should be able to select only the time between the open and close timings added by the admin.

for example: an office opens from 9am-5pm so if some one try books an appointment with the staff they should be only select anytime between 9am-5pm. or can be use some javascript validation too instead. Any suggestion or help with this issue???

I need to know how would I validate or allow user to select times between opening and closing hrs.

Any help would be appreciated.