The clock is pre-programed with the time so there is no need to worry about setting buttons. Just select your time zone at the bottom of the clock and turn on the DST if applicable. Plug the clock in to an approved electrical source. For quick adjustment for Daylight Savings Time, slide the DST switch at the bottom of the clock to ON to add and hour (+1 hr.). For Standard Time slide switch to OFF to subtract an hour (-1 hr.)Adjust the display brightness to your liking with the high or low dimmer control.The button cell battery CR2032 is pre-installed and is used for the back up battery and the time settings. It is in a screw-secured cabinet at the bottom of the clock. This battery will last for several years.