Love it or hate it, it's almost time to fall back again. This Sunday at 2 a.m., Daylight Saving will strike, and your iPhone's clock will adjust to show an hour "earlier" when you wake up in the morning. Perhaps the biggest positive about Daylight Saving at this time of year is that you'll get an extra hour of sleep Saturday night. But it also means that, through the winter, work days will feel longer, as the sun will start to set before you leave your desk. So, when you want to head to happy hour at 4:30 p.m. because it's pitch black outside, you'll have to struggle through those final painful hours at the office first. If you've ever wondered why we turn our clocks back in the fall and forward in the spring in the first place, the answer is surprisingly unclear. Daylight Saving has one of the strangest and most contested histories. Some say that it became commonplace in the U.S. during World War I, while others say that good old Benjamin Franklin dreamed it up in the 1700s. Why it's continued to the present day is confusing to many researchers, since it doesn't seem to offer any work benefit and, as some have argued, it also doesn't seem to conserve energy. To ensure your iPhone will update automatically Saturday night, head to Settings, General, then Date & Time. If the "Set Automatically" switch is toggled on, you're good to go. If not, switch it on to ensure your phone will change time on its own. (If only microwaves and stoves were as smart.) Historically, smartphones have sometimes had Daylight Saving Time bugs, so if you have somewhere really important to be on Sunday morning, you may want to set that alarm extra early — or even use an old-fashioned alarm clock as a backup. And, if you need to see exactly what time it is elsewhere (not all countries follow DST), you can download this useful World Clock app to keep things straight.