original: A night shift is either a group of workers who work during the night, or the period in which they work.
simplifications: A night shift is a name for a group of workers who work during the night, or it can be the period in which they work. A group of night workers or the time in which they work is called the night shift. A night shift can refer to a group of night-time workers or the period in which they work. A night shift can be a group of workers who work during the night or the time they work. A night shift is  a group of workers working during the night, or the period in which they work. A night shift can refer to a group of worker who work during the night or the time when they work. A night shift is a group of workers who work during the night. It can also describe the period in which they work. A night shift is the period which a group of workers work during the night. It can also refer to the workers themselves. A night shift can be a group of workers who work during the night. It can also be the time that they work. A night shift is a group of workers that work during the night