Another common variation of shifts is this:
Over a two week period:
Day (0600-1800) and Night (1800-0600)
Squad A: Mon D, Tues D, Fri D, Sat D, Sun D, Wed D, Thurs D
Squad B: Mon N, Tues N, Fri N, Sat N, Sun N, Wed N, Thurs N
Squad C: Wed D, Thurs D, Mon D, Tues D, Fri D, Sat D, Sun D
Squad D: Wed N, Thurs N, Mon N, Tues N, Fri N, Sat N, Sun N
In effect, it's two days on, two days off, weekend on, two days off, two days on, weekend off. Two weeks later, squads that were working day tours will work night tours, and vice versa.