We have 50 aircraft with approx 300 flights per weekday. There are 6 ops controllers on a pattern of earlies/lates/days/middles and float shifts.
earlies - 0500-1300
lates - 1600-0100
days - 0800-1600
middle - 1200-2000
float - home standby - contactable 0700am for 1hr then 1300 for 1hr to cover last minute sickness only and keeps the hours up for the rostered week.
We have 9 crew controllers that pretty much work the same hours. Some days when people aren't on leave we're falling over each other if its quiet but the bare minimum coverage is an early/day/late. Keeps the overtime rate down!