Overdue fees and fines calculation - things to know

In FOLIO, libraries can charge overdue fees/fines by the minute, hour, day, week or month.

For many libraries, the loan period interval and the overdue interval don't match. (E.g., a course reserve book loaned for three hours, with an overdue charge of $3 a day.) Because of that mismatch, the fee/fine system was designed to convert the overdue interval to its smallest unit - a minute - and calculate the fee/fine based on the minute. (E.g., if you put in your system that you charge $3 an hour for a fine, the system is actually calculating $3 for every sixty minutes.)

For many scenarios, this works, but for some scenarios it doesn't (particularly if you don't want to charge fines during service point closed hours.)

This issue is being examined - for more info, follow/comment on UXPROD-3276 - Getting issue details... STATUS

Item loan period, overdue charge	Item loaned at	Item due date	Item returned at	Service Point Hours / Charged for Closed?	How does the overdue calculation work?
Example scenario that works as expected
loaned for three hours, overdue $3/day	2:00 PM 9/1/2021	5:00 PM 9/1/2021	6:00 PM 9/2/2021	Service point open 24/7 / Charge during closed hours / No grace period	The item was overdue by one day and one hour = 25 hours = 1500 minutes. The fee/fine is $3/day, which is $3/1440 minutes. FOLIO calculates the number of intervals involved - 1500/1440 = ~1.07 intervals. It then rounds it up to the next largest integer - 2. So it's charging for 2 intervals. So the overdue fine is then the fine per interval (3.00) times the number of intervals (2) = $6.00.
Example scenario that doesn't work as expected:
An item is loaned for seven days, with an overdue fine of $3 day	2:00 PM 9/1/2021	9/7/2021 11:59:59 PM	Item returned at 9/10/2021 2 PM	Service point closes at midnight and opens at 8 AM the next day, every day - charge for closed hours is set to 'No'	The item was overdue by 2 days and 14 hours (strictly looking at the calendar.) That's 62 hours - 3720 minutes. But, the library was closed from midnight to 8 AM for three periods - the morning of the 8th, 9th, and 10th. So that means that there are 24 hours that shouldn't be counted. So then it becomes 62 hours - 24 hours = 38 hours. So if you take that to the interval stage - 38 hours / 24 hours - you get ~1.58, which FOLIO would round up to 2 intervals. So, it would charge $6. Note, though, that it was returned on the third day - so libraries would normally expect a fine of $9, instead of $6. So this scenario does not function as expected.