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back shift

noun British

a group of workers who work a shift from late afternoon to midnight in an industry or occupation where a day shift or a night shift is also worked
the period worked
US and Canadian name: swing shift
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012