Hi deberson,
Thank you for your purchase.

You can change Default Time Slot Step in General settings.

This setting allows you to choose a default length for the time slot step, which is used to “grid” the business hours and appointment durations. It determines the time slots step in which your appointments can be scheduled. The setting contains time slot step options ranging from 5 minutes to 8 hours.

For example, if you choose 10 minutes as the default time slot step, the working hours will be divided by a grid of 10 minutes, your customers will be offered to book appointments at 9:00, 9:10, 9:20, 9:30, etc., and the service duration will be configurable as 10 min, 20 min, 30 min, 40 min and so on.

"Example, instead of it showing as 1300 hours can I change it to 1 p.m.?"

Unfortunately at the moment  that is not possible with built in features of plugin. Thank you for your suggestion. We carefully follow customers requirements and try to implement most of them if they appear in requests from time to time, so we will add to our idea list and look into some possible solutions on plugin side in the future.

"Another issue that I am facing is the 2-hour slot times. It seems that only 2-hour slots times are available for display in calendar. If I want to show availability from 5 p.m. till 10 p.m, can this be done?"

You can set Default Time Slot Step on 1 hour and then set service duration of 5h and then you will have time slots available for that duration.

Best regards.