Sunrise & Sunset Time Calculator
Get a quick estimate of sunrise time based on latitude and the day of the year. The calculation uses a solar declination model to approximate the local sunrise in 24-hour decimal time.
Approximate astronomical values only. For navigation or safety planning, consult official sunrise tables.
Examples
- Latitude 40°, day 172 (June solstice) ⇒ 4.58 hours (≈04:35)
- Latitude 51°, day 200 ⇒ 4.13 hours (≈04:08)
FAQ
How do I convert the decimal hour to hh:mm?
Multiply the decimal fraction by 60. For example, 4.58 hours ≈ 4 hours and 0.58×60 = 35 minutes.
Does this account for daylight saving time?
No. The model returns local solar time. Adjust by your time zone and daylight-saving offset.
What about polar regions?
Latitudes above approximately ±66° may experience continuous day or night; the formula clamps to 0 or 24 hours accordingly.
Additional Information
- Based on the NOAA sunrise equation with a simplified solar declination term.
- For sunset time, add half of the calculated daylight duration to 12 (solar noon).