Phillip Glass is fine.
Contemporary in most classical world settings is anything written during or beyond WW1.
In modern music friendly settings, contemporary is pretty much post 1945.
In the contemporary performance unit during my degree, it was post 2000.
As you can see, it's a difficult thing to define... during most diploma exams here in the UK people get away with Debussy as their contemporary piece, so don't lose too much sleep over the word.