It's not just irresponsibility. It's called living. Enjoy life while you can. So you boss/parent/commanding officer is pissed at you. Big deal.

Friday I probably won't bother going to work. I'm getting a research assitant, and that's his first day. My boss will probably rip me a pair of new assholes for skipping out. Tough shit. Not the first time. Won't be the last. I don't really care, and the boss knows it. He also knows that I'll get the job done.

If you don't want to miss a day or just be useless for one, don't fucking show up.

You'll be happy later on in life, looking back and saying "I never let anything stand in the way of my public school education!"

Pfft. Don't kid yourself.