time commitment

Hi! I just wanted to see if I could get an honest answer on how big of a time commitment being in a sorority actually is. I've heard that the general answer is that it's what you put into it, which I'm sure is true to an extent, but I just remember having friends in my classes after formal recruitment last year having mandatory mixers multiple nights every weekend, and it seemed like they spent a crazy amount of time even just preparing for different sorority events. Does the level of commitment vary between chapters? Would it be a little more gradual if I came in doing informal recruitment?