the majority of airlines I've come across have ops jobs on 12h on 12h off, 4days on 4 days off alternating between days and nights. I've always wondered why changes every 4 days from days to nights instead of say a month of days followed by a month of nights. Constantly shifting your body clock can't be great for your health...I know I'm always knackered for the first two days of my shifts....not to put you off or anything airbusv
PS...you'd prob be better off asking Eastern rather than us lot!