Daylight saving is more than just an annoyance. When we throw off the alignment of our internal clock, or circadian rhythm, with the real-world clock, we’re doing more damage to our bodies than we realize. And there is data to prove it. Not only does the frequency of heart attacks go up in the week or two after daylight saving begins but it is also linked to cancer, depression, sleep disorders and lowered productivity. And it’s not just a problem in the U.S. — it affects people around the world.