Midnight is the transition time period from one day to the next: the moment when the date changes. In ancient Roman timekeeping, midnight was halfway between sunset and sunrise (i.e., solar midnight), varying according to the seasons. By clock time, midnight is the opposite of noon, differing from it by 12 hours.
Solar midnight is the time opposite to solar noon, when the sun is closest to the nadir and the night is equidistant from dusk and dawn. Due to the advent of time zones, which make time identical across a range of meridians, and daylight saving time, it rarely coincides with midnight on a clock. Solar midnight is dependent on longitude and time of the year rather than on a time zone.
In the northern hemisphere, «midnight» had an ancient geographic association with «north» (as did «noon» with «south» – see noon). Modern Polish and Belarusian preserve this association with its word for «midnight» (północ, поўнач – literally «half-night»), which also means «north».