In The PostPlague Trilogy, The Order (the new government) decides to set itself up around a Myers-Briggs type test, also known as The Test. It’s originally optional and the point is to make sure that in the new world people work at jobs they’re most suited for.
However, as time goes by The Test becomes mandatory and is given to people of younger and younger ages. It settles at the age of thirteen, before kids enter high school. This way children learn the skills that are most useful for the jobs that their Test scores tell them they should be doing. The score itself is called The Mark.
Everybody takes The Test on the same day every year, and I decided that society would have a difficult time giving up regular holidays. Therefore Testing Day is the first day of every year and everybody who turns 14 the following year take the Test on that day. That way citizens still celebrated New Year’s Day, but in such a way that it didn’t starts with mass quantities of alcohol, and with celebration over something that is very much a part of the new society.