alarm schedules: Unlike other alarm clocks, this one adds a everyday, weekday and weekend alarm time function. The alarm clock screen displays the day of the week for each day. 12 or 24 hour format to suit your preference. The volume of the alarms goes from low to high so you 't be startled. 4-level brightness adjustable: You can choose the screen brightness that is most comfortable in the morning, afternoon and evening. The screen is not light up at the lowest brightness level, you can sleep well at night, the power consumption is reduced. When the red low battery appears, replace all batteries promptly. USB or battery powered: When the alarm clock is powered by mains electricity, its screen is always on. With batteries installed and USB cable disconnected, the screen turn off after 10 seconds, any button and it light up again for 10 seconds, the scheduled alarms sound and other functions still work. Dual alarm with snooze: Dual alarm with switch, you and your family can have