We all like the extra hour of sleep that comes along with Daylight Savings Time, but for some people, the time change causes real headaches. Doctors say 'cluster' headaches typically start a few days after the Daylight Savings Time change and can last anywhere from six weeks to three months. Experts think the phenomenon, which is more likely to occur in men than women, is caused by circadian rhythms in the brain. There are medications that can alleviate cluster headaches, and some specialists will even recommend melatonin to prevent their onset. Patients are also often given an oxygen tank and a mask to relieve their pain.