Atomic Clock Digital The clock has a builtin receiver that automatically synchronizes itself with WWVB radio broadcast which will set and update time automatically every midnight no need to set manually It has four time zones selectable EST PST MST CST Digital Wall Clock Battery Operated This digital clock is supported by 3xAAA battery Not included No wires make it can be placed anywhere and the low battery symbol reminds you to replace the battery in time to avoid getting the wrong time due to low power Digital Wall Clock Large Display The LCD screen measures 62 in x 37 in and it displays time indoor temperature day and date Each section is showed separately allows you to read the content easily and quickly Atomic Clock with Auto DST With DST on the time would go forward or backward one hour automatically in daylight saving time no worry about time changing on that day If for no need it could also be turned off then AUTO DST disappears from screen Digital Alarm Clock The alarm could be turned on or off according to your need just click the button to set When alarm is set on there is a bell icon staying on screen The icon will disappear if alarm is set off When alarm goes off just click any button to stop it on the day 1224Hr Time Mode This atomic clock has two display modes standard time and military time When clock time is set for one mode the alarm time would be followed same automatically Also the temperature display could be exchanged from Fahrenheit to Degree by clicking the button on back