As mentioned elsewhere, Intel uses "Work Weeks" for everything. It might be great for manufacturing where a wafer takes a specific number of days to make it through the fab, but it inflicts horrible pain on the folks who have to deal with it and the outside world. My doctor, for instance, stubbornly pretends to not understand when I ask for an appointment in WW04!

December 30th, 2019 is WW01.1 2020 in this calendar. I bet no human in the world knows their WW 2020 birthday.