In retail closing shifts often end between 9 and midnight and opening shifts start between 7 and 9 am. A clopen is a portmanteau of closing one night and then opening the next morning, thus having as little as eight hours to eat, sleep, and shower between shifts. Depending on the kind of retail and the hours involved, clopens can be a mild annoyance or a brutal test of human endurance.
I'd love to hang out tomorrow night, but I'm clopening, so I won't get home until midnightand then need to be up at six am~
When you work in a retail/restaurant environment and you are scheduled to close up shop around 10-12 at night, and then are also expected to come back and work an opening shift the next day around 6-8. This usually only allows for a person to sleep 3-5 hours in between shifts because they still have to take the time to travel home, wind-down, eat and/or feed your children, and/or significant other (if pets are involved, they need to be fed also and possibly walked), maybe laundry, shower, sleep and eat, shower and travel back...It's like they never leave and also can cause severe pain in the feet, legs, hips, back and brain.