я работал в ночную смену
I worked the night shift
I was working the night shift
I worked (/was working) night shift(s)
(s) - если речь не об одном разе
http://www.independent.co.uk/life-style/health-and-families/health-news/three-million-britons-working-night-shifts-and-endangering-their-health-10438592.html
I work at night shift