How many things do you do 12 times a year simply because there are 12 months in the year?
How many things do you do 5 or 7 days a week simply because there are 5 days (in a work week) or 7 days in a week?
In other words, how many things in your life are limited by arbitrary rhythms of an arbitrary calendar?
What about 13 months in the year (lunar months) instead of 12?
What about a 4 day week instead of 5 day week?
What about 6 or 8 week blocks?
Why not?
Be weird. And let the rest of the world flip the calendar.