Shift work is work designed to utilize 24 hours of the day.
Convenient store clerks, large-scale factory workers, police officers, etc.
"Shift work, tough work for the busy convenience store clerk
Two feet that hurt, going insane
She's mad at some lad
Drove off and didn't pay for his gas and he won't be the last
'round the clock pain
Work seven to three
Three to eleven
Eleven to seven"
"Shift work" by Kenny Chesney