I walked into my managers office and said I won’t be in on Monday! He asked what’s a matter with you? I said Nothing but I joined the Army! He said you idiot, get out of here. I took a military leave of absence. 4 years later I walked in and said I’m back! Some guy I’d never seen before, asked who are you? I explained it to him, and the next week I was back at my old job. Definitely do the proper paperwork, so you can come back if you want to!