Count actual working days between two dates — and find the day you go back after leave.
The weekend in Saudi Arabia is Friday and Saturday. Office roles usually work Sunday to Thursday, while a great deal of construction, retail and site work runs six days with only Friday off. Both patterns are handled above.
This catches people out. Annual leave in Saudi Arabia is normally counted in calendar days, so the weekends inside your leave are part of the count. Take thirty days from a Sunday and you are back four weeks later — not six. Some employers count working days only, which is more generous; check your policy.
If your leave finishes on a Thursday, your first day back is Sunday. The planner above skips the weekend for you, which is the detail most people get wrong when booking a flight home.
Eid al-Fitr and Eid al-Adha move each year because they follow the Hijri calendar, and National Day falls on 23 September. Add the dates yourself above — hard-coding them would go stale, and the exact days are announced close to the time.