From asking How did the ancient cultures determine that the year was actually a fraction of an extra day beyond 365 days? I'm now wondering how cultures like Ancient Egypt, with their 12-month, 30 days per month solar calendar year (360 days), plus 5 or 6 feast holidays to make it 365 or 366 (leap year) days per year.
How did they justify having "random extra days" in their calendar? How did other cultures justify this similar thing in their calendars?