original: a night shift is either a group of workers who work during the night , or the period in which they work .
simplifications: 1 . a night shift is either a group of workers who work during the night , or the time when they work . a night shift is either a group of workers who work during the night , or the time at which they work . a night shift is a period during the night when a worker or group of workers do their work . a night shift is work by people at night . a night shift is either a group of workers who work during the night , or the time span in which they work . a night shift is either a group of workers who work during the night , or the stage in history in which they work . the night shift pertains to a group of workers , or the period they work . a night shift is a group of workers who work at night or the night time period when they work .