im so sorry for taking forever to answer these im so lazy
idk i feel like all together theyre a rly spontaneous trio, the only traditions they have are morning routines and like whatever witchy stuff jehan does but thats mostly just jehan lol.
for anniversaries, they just spend the day together doing whatever ghfhjhg they get a full 24 hours without having to be with les amis (enjolras flat out dies w/o combeferre and courfeyrac LMAO)