On Sunday, most Canadians will be turning their clocks forward one hour to mark the start of Daylight Saving Time. It heralds the beginning of the shift into longer daylight hours and warmer seasons, but why do we spring forward and how does losing just a single hour of sleep tamper with our internal clocks?

Here’s everything you need to know about Daylight Saving Time, its purpose and how it can affect your body and internal clock.

When is Daylight Saving Time this year?

The spring forward occurs on March 12. On Sunday at 2 a.m., clocks jump forward by one hour, which means the sun will rise later but daylight will extend into our evenings. You’ll lose an hour of sleep initially from Saturday night into Sunday morning, though.

What’s the point of Daylight Saving Time?

DST was created to cut energy costs – if work hours were during daylight, people could save money on candle wax, and later on, electricity. Both were incredibly costly at the time.

Story continues below advertisement

It was phased out but re-introduced during the Second World War. In summary, it saves energy, but it also saves lives as our evenings are lighter for longer periods of time so highways are brighter during the drive home, for example.

READ MORE: 4 ways Daylight Saving Time affects your health, internal clock

Which parts of the world follow DST?

More than 70 countries and one-fifth of the world’s seven billion people follow DST. There are some exceptions, though.

In Canada, Saskatchewan, parts of B.C. and Ontario and Quebec’s north shore don’t follow the time change.

WATCH: Alberta mulls an end to Daylight Saving Time

2:08 Alberta mulls an end to Daylight Saving Time Alberta mulls an end to Daylight Saving Time

In the United States Arizona and Hawaii don’t observe daylight time. China, India, Japan and several other nations also don’t abide by DST.

Story continues below advertisement

How does losing an hour of sleep affect our bodies?

For starters, our appetites throw us a curveball. If you aren’t sleeping well, your metabolism takes a hit, along with your eating routine. You could be encountering more cravings for junk food or even a loss of appetite.

Dr. Colleen Carney, a Ryerson University professor and sleep specialist, says that sleep is just as valuable as a healthy diet, drinking less alcohol and exercising more.

It’s a bit of a vicious cycle – sleep regulates our appetites because it balances out hormones.

READ MORE: Here’s why your sleepless night is giving you the munchies

“An hour is enough to feel the effects. Think of it this way, what if you ate at 6 p.m. most nights but then you crossed over into a different time zone at 6 p.m. and had to wait an extra hour to eat when you are already hungry? You would feel the effect of just this one hour,” Carney told Global News.

“We have clocks all over our body, including our stomach and we have rhythmicity to things like eating, alertness and sleeping. The spring is particularly tough because we are a sleep-deprived nation and losing an hour of sleep will compound an already difficult situation for some,” she said.

Story continues below advertisement

Your heart health is tampered with, too. Time and time again, research warns that losing an hour of sleep increases your stroke risk for the following two days, especially for seniors and those with cancer.

Finnish doctors out of the University of Turku suggest the rate of ischemic stroke – caused by a clot blocking blood flow to the brain – is eight per cent higher during the first two days after a DST transition. After that, the disparity tapers off.

READ MORE: Daylight Saving Time linked to higher stroke risk in the following days, study warns

“Stroke risk is higher in the morning hours and we know from previous studies that DST changes slightly shifts the timing pattern of stroke onset,” the researchers said.

Other findings point to a seven per cent increase in heart attacks in the first three days after DST.

How else does the time change affect our daily lives?

We’re also more accident-prone, according to research. A handful of studies point to a rise in car accidents on the first workday after Daylight Saving Time.

“The loss of one hour’s sleep associated with the spring shift to daylight savings time increased the risk of accidents,” one study, published in the New England Journal of Medicine, concluded.

Story continues below advertisement

READ MORE: How Daylight Saving Time affects your internal clock

This study reported an eight per cent increase in traffic accidents.

A University of Colorado study pointed to a 17 per cent spike in traffic-related deaths on the Monday after DST.

You’re less productive at work, too. In 2012, scientists at Penn State, Virginia Tech and Singapore University warned employers that sleepy employees will be less hard working and will be more likely turn to the Internet to kill time post-DST.

After analyzing six years of data from Google, the researchers say that web searches linked to entertainment increased by 3.1 per cent the work day after clocks jumped ahead. Words like “YouTube,” “Facebook” and “ESPN” spiked in the online giant’s search records.

READ MORE: Daylight Saving Time leads to ‘massive productivity losses,’ study says

The time change is linked to about 8.4 minutes – or 20 per cent of the assigned task time – of “cyberloafing” every hour.

Eight minutes is small in the grand scheme of things, but the study reminds readers that about one-third of the world practices Daylight Saving Time. In total, that’s a lot of company time.

carmen.chai@globalnews.ca

Follow @Carmen_Chai

Story continues below advertisement