Online Tool Store
Sunrise Sunset Lookup
Calculate sunrise, sunset, and daylight length for any latitude, longitude, and date, computed offline using solar position formulas.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Sunrise
Sunset
Daylight length
Calculated offline using astronomical formulas - times are approximate (±1-2 minutes) local solar time and don't account for atmospheric refraction or local timezone rules.
How the sunrise/sunset lookup works
- Enter a latitude, longitude, and date - or use your current location.
- Sunrise and sunset times are calculated offline using solar position formulas.
- See the resulting times (in UTC) and total daylight length.
FAQ
How are sunrise and sunset calculated offline?
Using standard solar position astronomical formulas (based on the day of year, latitude, and longitude) to compute the sun's declination and hour angle - no external API or internet connection required.
How accurate are the results?
Typically within 1-2 minutes of official published times, though the formula doesn't account for atmospheric refraction or elevation, which can shift results slightly.
What does "polar night" or "midnight sun" mean?
At extreme latitudes during certain times of year, the sun may not rise (polar night) or not set (midnight sun) at all - the tool detects and reports these cases.
Can I use my current location?
Yes - click "Use my current location" to fill in your latitude and longitude automatically via your browser's geolocation (with your permission).
How we compare
| Feature | Online Tool Store | Weather app | Astronomy almanac |
|---|---|---|---|
| Works fully offline | ✓ | ✗ | ✓ |
| Any coordinates, any date | ✓ | ✗ | ✓ |
| Instant, no lookup tables | ✓ | ✓ | ✗ |
Useful for photographers, hikers, or anyone planning around daylight hours without needing an internet connection.