The Science Museum alarm clock is the most accurate clock of its size in the world, updating 3 times a day with up to the millisecond precision from the atomic clock in Frankfurt. Where the average clock loses up to 15 minutes a year, the scientific talking alarm clock will stay 100% accurate as long as there are batteries in it! Because it's radio controlled, it will automatically take into account leap years, daylight saving time & anything else a standard alarm clock wouldn't be programmed to adjust for.