No it isn’t.
But it does assume that each year is exactly 52 weeks long.
(
wheresthefish Partly filled with wrong, Thu 22 Jul 2021, 18:44,
Reply)
^
Every 28 years needs an extra week
(
Fadgebadger Sweaty sumo wanks for everyone!, Thu 22 Jul 2021, 18:59,
Reply)