Sunrise & Sunset Calculator

Stacked conventions: refraction varies with temperature and pressure (the standard 34′ is an average — cold dense air lifts the sun more), elevation matters (from a 1,500-m mountain the horizon dips and the sun rises minutes earlier), and some tables compute for the city centre while you stand 20 km west (each degree of longitude shifts times 4 minutes). Almanac-grade agreement needs identical assumptions; for alarm clocks and photo shoots, ±2 minutes is the honest envelope.

The equation of time: Earth's elliptical orbit and axial tilt make true solar noon drift up to ±16 minutes against clock noon through the year. Around the June solstice, solar noon is drifting later each day — so the earliest sunrise lands ~a week BEFORE the solstice and the latest sunset ~a week after (reversed for December: earliest sunset in early December, latest sunrise in early January, the famous dark-morning January grievance). Day LENGTH still peaks exactly at the solstice; its endpoints just slide together.

Latitude sets the tempo: near the equinoxes at mid-latitudes, times shift 1–2 minutes per day (a fortnight moves sunset by 20+ minutes — why spring evenings seem to arrive suddenly); near solstices the curve flattens to seconds per day. At 60°N the equinox slope reaches 4–5 min/day, while at the equator the whole annual swing is barely half an hour. This is also why 'sunrise at 6, sunset at 6' is everyday truth in Singapore and a twice-a-year event in Stockholm.

When latitude and declination conspire so the sun never crosses the 90.833° zenith — |φ| > 90° − 0.833° − |δ| roughly — there's no rise or set to report: above the Arctic Circle in June the sun circles the sky (day length 24 h), in December it never appears (0 h). The tool shows — for the times and the honest extreme for day length. The transition zone is dramatic: at 67°N, between late May and mid-July, a single week swings from normal nights to none at all.