Are you "working" when you are asleep but at work? Should you be paid for being on call when you are at home?
A recent study found that delaying meals because of working shifts can mess with your internal body clock. Here are five ways to survive the slog of shift work.
1 EAT WELL
When the clock strikes midnight, your body tells you to sleep, not to eat lunch.
This is why shift work can play havoc with your dietary health.
New research shows that delaying meal times or having meals at irregular times can affect your internal body rhythms. The study, published in the journal Current Biology, found that a five-hour delay in meal times causes a five-hour delay in blood glucose rhythms.
"We think this is due to changes in the clocks in our metabolic tissues but not the master clock in the brain," said Dr Jonathan Johnston of the University of Surrey, one of the authors of the study.
It is easy to let your blood sugar levels dip too low - particularly on busy shifts - so the trick is to plan ahead and organise what to eat during and around shifts.
"Make sure the fridge is stocked with healthy choices," said Ms Suzy Reading, a chartered psychologist. "One way to do this is by cooking meals in batches and reheating them through the week."
She also recommends taking pre- prepared meals with you if it is difficult to get healthy options at work.
What you eat can make a big difference, said Mr Chris Simon, a personal trainer. "If you want to have a high amount of energy to pull you through a shift, you should include brown rice in your meal. It contains manganese, which helps produce energy from protein and carbohydrates."
Mr Simon suggests meals with about 3g protein, 3.5g starch (containing manganese) and around 6g of leafy greens. "This will give you a lot of energy, even at the end of your shift," he said.
It is unlikely that you will finish a night shift and want to head straight to the gym for a workout.
However, you may want to plan a few activity sessions around your shifts, whether it is a quick swim before you start work or a long walk on your day off.
"When it comes to exercise, fit it in whenever you can," said Ms Reading. "Any movement will do, including following some of the exercise routines on YouTube."
Remember that exercise is not just about physical health, it is also about mental health, she said.
"Any movement, even gentle forms, has a potent antidepressant action. So, if energy is low or you are exercising before going to bed, opt for something soothing, such as a yoga session or a walk."
3 TAKE BREAKS
All shift workers should be given adequate rest breaks (at least 20 minutes if the working day is longer than six hours) and those who are doing monotonous or hazardous work must be given more, said Ms Laura Livingstone , a partner at law firm Gordon Dadds.
"Night workers should work no more than eight hours in any 24-hour period," she said. It is in the employer's interests to have a healthy workforce, she added.
4 ENJOY A SOCIAL LIFE
If you work unsocial hours, including weekends, it can be hard to fit in a social life. But stressing about it is not good for your mental health or your relationships, said Ms Anna Percy-Davis, executive and careers coach at Well Aware.
"When it comes to enjoying time with friends and family around awkward shift-work hours, quality rather than quantity needs to be the focus," she said.
She suggests finding ways to spend time together and ensuring that those closest to you appreciate that you may be tired or your time with them is going to be limited.
"This does not mean you have to act like a martyr or that you expect loads of sympathy," she said. "It's about making those moments when you are together fun rather than stressed. Spending time with family and friends requires more effort when you are a shift worker, but it is not impossible."
5 HOW TO SLEEP AND UNWIND
Sleeping during the day can be a nightmare with noise and light (eye pads and earphones can help), and can have long-term effects.
While you could try resetting your body clock by sleeping under the stars on your nights off - a study suggests that camping can help reset circadian rhythms - that is not a practical year-round solution.
Instead, try sleeping in a darkened room with your smartphone switched off, sipping chamomile or lavender tea and using an app for meditation to help you wind down.