Off Day

Off Day is an open-source holiday alarm clock with built-in templates for multiple countries. It lets you mark Off Day or Work Day and follow automation steps using Shortcuts to disable alarms on days off.

You can also manually set your holiday work schedules, giving you full control over whether a day is Off or Work. This is a paid app; ensure it fits your needs before purchasing. The project is open-source, so you can compile it yourself or support the project by purchasing.