[om42]

9/80 schedules are more popular in defense, at least from what I've seen. There's some unintended consequences (to me) of it. PTO/holidays can get weird, do you get 9 hours of paid time? Do you get 8 and shift your hours? Its mostly a problem when teams have a mix systems and there isn't a standard.

When I was at LM a few years ago, some teams were on a different 9/80 pattern (different Fridays off), and some still on the regular 10/80 schedule. So on Fridays you basically had significantly less people in the office and it was never the person you needed to get work done. Basically made Monday to Thursday the regular working week with Friday being there if you really needed to get work done.

Think the different schedules was a combination of LM employees, employees that were in the union, and external contractors having different contract requirements.