Med thumb summer solstice

We’ve officially been allowed to rock white jeans since Memorial Day. But according to the astrological calendar, summer technically begins on Monday, June 20, the longest day of the year in the northern hemisphere, also known as the Summer Solstice.

Given that light plays such a vital role in regulating the body clock, does extended daylight affect the sleep-and-wake cycle? We know darkness triggers the release of melatonin, thereby telling the body it’s time to wind down. Can too little nighttime disrupt the process?

Science says yes, theoretically, maybe. In this age of blackout shades and alarm clocks, too much light is probably no big deal, according to Steven Feinsilver, a pulmonologist and sleep medicine doctor at Mount Sinai Hospital. Insomnia is actually less of an issue in the summer, and the abundance of light, Feinsilver explained, makes it easier for people with wonky sleep schedules to get back on track. Here’s what you should know about shut-eye in the season of lingering sun.

1. Don’t underestimate the power of light

“The main thing that sets your body clock, by far, is light,” Feinsilver said. “The biggest consumers of sleeping pills in the world are in Finland, supposedly. If you’re close to the Arctic circle, you have problems both times of year — when it’s really dark all the time, and when it’s really light all the time.”

2. Insomniacs can use morning rays to their advantage

“When we’re treating people with insomnia and many other sleep problems,” Feinsilver explained, “I tell them to get up in the morning, open all the blinds and go outside. Obviously that’s a lot easier to do when there’s light out.”

According to Feinsilver, insomnia is more common during the winter than summer.

“People get into more problems when they’re waking up to go to work in the morning and it’s dark — you don’t have that natural source of light turning off melatonin in the morning. In addition to being depressing, the dark isn’t something that wakes people up very well.”

3. Drastic shifts in light exposure are what cause trouble

“In general, we tell patients you can change your body clock about an hour a day,” said Feinsilver. “People who get up at 6 a.m. Monday through Friday, and sleep until noon on weekends — that doesn’t work. You can’t change your body clock that much.”

4. We crave natural light, which is hard to fake

It’s not 1790. We have the ability to block light fairly easily. But, as Feinsilver explained, creating the real thing is harder.

“You can avoid direct exposure to light if you want to go to bed — get good blinds, and you’ll be okay. [In summer], I can tell patients to let the morning light stream in. Whereas in the winter, when it’s dark in the morning, it’s a little hard to do it naturally.”

5. If anyone’s going to suffer, it’s night owls

Illuminated evenings may take the most toll on people who already have a delayed sleep phase — e.g., teenagers who love to stay up and sleep in. But, it’s also easiest to force oneself onto an up-and-at-’em schedule when the sun beams through the window at 6 a.m.

Summer is, literally, the time to seize the day, even if you’re naturally invigorated by moonlight.

6. The solstice is an opportunity to reset your body clock

If you naturally rise at 10 a.m., and want to get up at 7 a.m., force yourself out of bed an hour earlier each day.

“You need to expose your body to as much morning light as possible,” said Feinsilver. “Then, go to bed seven or eight hours before your new target wake time. But, don’t go to bed any earlier than 11:30 or so, no matter how rotten you feel. You might feel miserable for a bit, but over several days, if you do that, you’ll get on a new schedule. Sleep is a powerful biological drug.”