How long can the Glowforge sit without being used?

I bought a glowforge for my graphic arts program, and wondered do I need to come and run it in the summer, while there is no school?

While there are no parts that I know of that need exercising a glowforge tends to get very sad if not fulfilling its purpose in life.
You should stop by randomly about once a week and cut a few things and tell it how useful it is.