[paradite]

Nicely done. One comment: It took me a while to realize the numbers on the top right triangles are week numbers in the year. Typically I am not concerned with that, not sure if there are general use cases for the week number.

[hiergiltdiestfu]

Week numbers are important in scrum and release plannings, and in university (someone mentioned "parity" - some courses happen in odd weeks, others in even weeks). Keep them, I miss them :D

[qw]

Week numbers are used a lot in my experience. Features are often promised by week X. Events, work schedules and even vacations are also often referenced by week.

[wingerlang]

It could vary by country as well, when I grew up and went to school it was used a whole lot. I don't remember the last time I saw it though, and since moving abroad I definitely haven't seen it.

[Freak_NL]

It varies a lot by trade and profession. Any place where complex scheduling is part of the job tends to use them (e.g., schools, manufacturing plants, accounting).

[rplnt]

Me neither anymore, but I was concerned with week's "parity" in school. I.e. whether the week was even or odd.