Flexible Hours

I have this problem as well.

Allow client to pick the timing they required based on how many hours it is choose to subscribe.

The issue is that the booking slot seems to be pre-determined by the system. Client cannot pick anything like 5.30 to 6.30 if it pick 1 hour services as it will allow 5pm to 6pm. and if client want something like .5.30pm to 7pm, it wont allow this kind of timing selection

I offer something similar. One of the things I do in the business I use bookingpress for, is get hired for birthday parties. People can hire me for 1 and a half hours, up to 3 hours (I charge a flat rate for this, and an additional fee for additional hours beyond the first three). They can choose to hire me for whatever amount they want (within my work hours that day). However presently the services are set up so they can only book me for an amount of time the service is set for. This potentially is longer than a customer might want to hire me for, and blocks off all that time in my calendar. This means if someone wanted to hire me shortly after I am done at another party that same day, they would be unable to as that time would be blocked off in my calendar.