The time of day when, on average over the year, the Sun is furthest away from its highest point in the sky. Midnight is 0:00 in universal time. Midnight itself is neither a.m. nor p.m., but the minute between 12:00 midnight and 12:01 is a.m., so midnight itself is often denoted 12:00 a.m. on digital clocks in the U. S.