Incorrect absence duration being considered on a day with half day public holiday

We have an employee on a Time based Work Schedule, which has 2 shifts attached to it. The shifts are 4 hours each, from 8 am - 12 pm, and 1 pm - 5pm.

When this employee applies for a half day absence on a day where the 2nd half of the day has a public holiday attached, the system considers it as a full day of absence. Even though the absence start and end time is taken as 8 am - 12pm, the absence duration comes up to 1 day. On normal days, the same 8 am - 12 pm absence hours comes up to 0.5 day, the incorrect behavior is only in the scenario where there is a half day public holiday.