I just put in my 4 week notice and asked if I could use my 1 week of vacation in that period and my boss said I could only use 3 days of my vacation

My employer has know about me interviewing with another company for about a month now and I finally got the offer yesterday and accepted it and then I turned in my 4 week notice today thinking that would give them enough time to find a replacement and train them but I guess not. So infuriating smh.