Custom working days is a tool that you can use to establish a date that normally would be considered a non-working day, but for your company, or for specific employees in your company, it needs to be a considered working day.
For example, you may have Christmas Day as a public holiday in your calendar, but your business is open that day, so you make Christmas Day a custom working day. If someone assigned to that custom working day books that day off, it will count against their time off balance.
Click on your name on the top right, then click Settings.
On the settings menu, click Calendar, then Custom working days.
Click Add working day.
Enter a name.
Select the date.
If required, select Repeat every year.
Select which employees this custom working day applies to. You can select all or select specific people.
Once done, click Create.