I say its 3-11. Wikipedia says it and amazon does about the dvds yet SOME MODS here think its 4-12. If thats so they sure get out of work early as many episode they talk of getting out at 11 but usually say 11:30. I recently tried to change the show summary to 3-11 from the now 4-12 but the request was denied and the mod left the note to me:
The Third Watch tour is 4-12, not 3-11.
Now I know they refer to the next shift as Midnights which makes it confusing but still The Third Watch shift is 3-11. Comments and someone please submit that to the Summary so it can be correct.