Varying Weekly Appointment Hours

I would like a monthly schedule for appointment hours be available instead of only offering a set schedule each day of the week? Example- I am available on Thursday July 28th from 2-4pm but the following Thursday August 4th from 12-2pm. Please offer the option to have different hours each week without changing them the week of. Customers want to book several weeks in advance & we don't have a set schedule each week.