[Koha] Koha calendar hourly settings

[Iddi Juma]

Dear All,

I am using Koha 3.12 because of its provision to issue items on hourly
basis which I need for my 2-hour short-loan services. However, I
cannot find any settings on the Koha calendar to help me set working
hours for each working day so that users who borrow short-loan items
towards the closure of the library say at 10:00pm are not charged
overdue fines for the rest of the night  and any other times the
library remains closed. My calendar is something like:

Mondays - Fridays     8:00am-10:pm
Saturdays                11:am - 5:00pm
Sundays                  Closed

Any ideas on how to go about this?

Regards
I Juma