Update: PR1.2 firmware is now available - remember that you don't need this if you're running the new version.
Calendarrr automatically updates the Calendar icon on your N9/N950's home screen with today's date, freeing it from being stuck forever on the 21st. While Calendarrr is similar to thp/pam's calenderr script, Calendarrr:
Calendarrr is compatible with PR1.1 and PR1.1.1 firmware only. The upcoming PR1.2 firmware includes this functionality "out of the box", so this program won't be needed anymore then.
Note: If you have calenderr ("Dynamic calendar icon" on Nokia Store) installed, remove it and reboot before installing Calendarrr. Make sure to remove Calendarrr before trying to upgrade to PR1.2 (you won't be able to otherwise).