If a clock uses a standard seven-bar LED display, the most bars are lit at 12:08 and 8:08, which light 20 bars. Eight is the digit that lights up the most bars, illuminating all seven. Zero lights up six, while one and two account for seven bars together.
If the clock is set for military time, 8:08 p.m. is the time that illuminates the most bars of the LED display. 8:08 p.m. is 20:08 in a 24-hour display, which illuminates a total of 24 bars of the 28 available.
The time that lights up the least number of bars on a standard LED clock face is 1:11, with a total of six bars.