Headed for Europe? Today is the day countries of the European Union "spring forward," setting their clocks ahead one hour, from Standard Time to Summer Time. Their switch comes two weeks after most of the U.S. moved to Daylight Savings Time. During that period, the clock difference between Baltimore and London was just four hours. Now, it's five hours once again. European Summer Time is one hour ahead of Coordinated Universal Time (UTC), the global standard.