Did you know that staying up just an hour or two later on the weekend can wreak havoc on your sleep, not to mention your mood? The name for this phenomenon is “social jet lag” – although it’s not a clinical condition, sleep psychologists have noted that more people aren’t sticking with the same sleep-wake schedule through the week. And that comes with a price: Staying out until the wee hours Friday and Saturday nights and then sleeping in both days can throw our body clocks out of whack. So much so that we can have trouble adjusting to our “regular” sleep time when it’s Sunday night, leaving us dragging and grumpy the next day. Our internal body clocks get thrown out of whack, which in turn throws off our appetite and our sleep patterns for the next day. One sleep hack that can help: get a solid night’s rest through the week, so you’re not going into your weekend with sleep debt. If you need to, take power naps to catch up.