In 1989, 20 years would not be enough seniority to work daywork in the 1st, 3rd, and maybe the 5th too. I was hired with a class of 31. When our 20 came around, about 25% were already gone. I left with less that 23 years in. There were only 4 left at that point. Now - unless he retired recently - there is only one. So we all left with about as much seniority as the FTOs in the 3rd had at the time, as they were finally able to get off the 4-12 shift. None of us stayed long enough to see day shift,