It is also the first day of the Spring (or Vernal) Equinox (in Mandarin, chūnfēn) solar term.
春分
Not much to say about this solar term's name, really... Pretty matter-of-fact. Interesting that the charcter for equinox is the same that is used for minute (the 60th part of an hour), and for the 100th part of a yuan, the currency unit. These are all ideas associated with division, so maybe "divided part" is the core meaning of this character. It works well as a pictogram - the bottom part is the radical meaning knife (you can almost make out the picture of a cleaver), and the top part represents the thing being divided.


