Official calendar link:
https://app.fantasy-calendar.com/calendars/36438261940080debea6c4fc8bd62955
This is a simple version on here, on Kanka.
Work Days Tenday (week), Days 1-7, 11-17, 21-27, that make up a working week.
Tenend (weekend) Days 8-10, 18-20, 28-30, that make up people being off, working shorter hours, less staff.