NOTE: When powered by USB alone, the screen can be stay on and there is no memory function after power off. DUAL POWER SUPPLY: This digital alarm clock comes with 6.5 in large screen and large font so that you can easily read the digital display. It supports USB power supply. BRIGHTNESS & NIGHT MODE: Digital alarm clock provides different levels of brightness, which can be adjusted to a comfortable brightness manually or automatically to protect your eyes and save energy at night. 5 DISPLAY MODES: This upgraded version the alarm clock has 5 display modes: clock mode, alarm mode, date mode, temperature mode, night mode, which can meet your daily needs. WORKING DAY MODE: This alarm clock also comes with three working day alarm modes. You can set the time interval: Monday to Friday, Monday to Saturday, and Monday to Sunday.