Summary:
If a timeoff is booked for multiple days, and a weekend falls within that period, it would not be counted. This is how the application works when time off taken spans over a holiday(s) or weekends.

More Information:
Example:
If I book a Time Off for two days Friday and Saturday, Saturday is not counted because Saturday is set as a Weekly time off in user profile. Therefore, although 2  such days are selected on the calendar, the time off taken for the time off type accounts to only one day.

Please refer to the attached Screenshot: