Previous facility we had 10-6 but you can't flex early or late because you've already worked 78 hours in the pay period. So if you're late you take leave, and if you're early you have to get credit approved.
It's a lot easier to fill gaps in staffing and allow you to take leave with 12-8, which is why it's preferred. Every year when you have people switch days on and off the Sat-Sun mid.
The way the rugby dogs facility does it is wrong, air traffic is not flex 80 shifts, so you have to have 40 hours of straight time per week, not just 80 per pay period. If you work a 12-8 for the first week, you come into your next mid with 40 hours worked for the week.