ISS Shifts go for 8.5hours to 9hours. Normally 8.5 because we are efficient at handover.
Morning shift (“Orbit 1”) is from 0400-1300 GMT
Afternoon shift (“Orbit 2”) is from 1200-2100 GMT
Night shift (“Orbit 3”) is from 2000-0500 GMT
The breaks are a fun questions: So… we have great real time satellite coverage but the satellite system we use is many miles above us in a very high orbit (the ISS is in Low Earth Orbit at just 400km) and when we pass underneath and switch between the communications satellites every hour or so there is a small gap. Sometimes the gaps are a few seconds, sometimes a few minutes. At high beta angles they can be 20mins. We like these gaps. They are the only times Flight Controller can take a break, leave the control room and get a coffee, go to the loo etc!