Estimates, not observations
Every time on this site is computed, not observed. The model assumes a level horizon at sea level, standard atmospheric refraction and the upper edge of the Sun. Hills, buildings, your height above ground, unusual air temperature and pressure, and cloud all move the moment you actually see the Sun rise or set, sometimes by several minutes.
Time zones and dates
Clock times follow the IANA time-zone rules shipped with your browser. Governments change daylight-saving rules at short notice, and rules for dates far in the future are projections. A custom location needs the correct zone name; coordinates alone do not determine it.
Not for official use
Do not use these times where a legal, regulatory, navigational, aviation, hunting, fishing or safety definition of sunrise, sunset, twilight or daylight applies. Those definitions and their authoritative tables come from the relevant authority. The site also does not provide prayer times or any religious timetable.
Accuracy review
Times have been checked against the engine’s published test fixtures and for internal consistency across time zones, the date line, daylight-saving transitions and polar latitudes. Independent, city-by-city comparison with observatory tables has not been completed. Reports of discrepancies are welcome through the contact form.