The R52BHQD204 is 12" double dial ceiling quartz clock ideal for schools, hospitals etc. It features a microchip with an internal lithium battery that keeps track of the current date and time. The microchip is programmed to make the daylight saving time change at 03:00 am eastern, 02:00 am central, 01:00 am mountain and 12:00 pacific time twice a year. In the Fall, the movement will automatically move the hands forward 11 hours, at an accelerated speed, to achieve a set back of 1 hour from daylight saving time to standard time. In the spring, the movement will move the hands forward one hour, at an accelerated speed, to achieve the advance of one hour.