A 302 can actually be up to 120 hours
303 is up to 20 days
304 is 90
There's also a 305, which I believe is up to 180
And technically a 306, but that has to do with transferring involuntary commitment patients to another facility or something.
Like I said in another comment I work in PA and my wife happens to work at a psych hospital so I get to hear all about this stuff.