I didn't work quite long enough to get 5 weeks because I retired early...but I had 4 weeks which I broke up. I'd attach my days to Fridays and/or Mondays so it seemed like I had a lot more time. I never could accumulate may sick days but I had enough vacation days that even though my retirement started Feb 1st, my last day was Jan 22nd.
5 weeks and a few days. However, it wasn't called vacation per se; you got a bank of hours, to schedule for vacations or non-federal holidays or sick time not to exceed 3 consecutive days without a doctor's note.