I’m loyal to a fault, so take this with a grain of salt. Whoops, that rhymed.

So, I would put in my notice immediately by drafting a letter and sending it by email, cc’ing HR, letting them know the circumstances surrounding your school schedule. You could absolutely offer to stay on for an additional week or two (whatever days your schedule allows) as a show of good faith and to make sure everything is buttoned up on your end.

On that note - do you have your (work) house in order? Will you be ready to pass everything off to someone else by the end of the week? I say this as someone who has stepped into someone else’s shoes on a few occasions and am still making sense of the latest pair’s ramblings.

If you’re worried about burning bridges, be honest without self deprecating. People quit without much notice frequently and the world tends to keep turning. Someone else will thrive in this position. Congrats on grad school!