Explain it like I'm 12
The calculator estimates sunrise, sunset, day length and solar noon from the entered location and date using a standard simplified solar-position algorithm.
Sunrise and Sunset Calculator
Estimate sunrise, sunset, solar noon and day length from date, latitude, longitude and UTC offset.
What-if check
Solar inputs that move the clock
The approximation depends on date, latitude, longitude and the selected UTC offset; changing any one of those can move sunrise and sunset.
| Check | Value | Note |
|---|---|---|
| date | 2026-07-16 | day 197 |
| latitude | -33.8688 deg | north/south position |
| longitude | 151.2093 deg | east/west position |
| UTC offset | UTC+10 | manual local clock setting |
| current output | 06:58 sunrise · 17:05 sunset | approximate solar event times |
Visual proof
Result path
2026-07-16 at -33.8688°, 151.2093° with UTC+10. Day length 10h 07m; approximate solar noon 12:01.
Source references
- NOAA Global Monitoring Laboratory: Solar Calculation Details — solar-position calculation reference
Formula
Approximate solar event times are calculated from day of year, longitude hour, solar mean anomaly, true longitude, right ascension, declination and the sunrise/sunset hour angle.
Worked example
Enter Sydney at latitude -33.8688, longitude 151.2093 and UTC+10. The page converts the date to day-of-year, estimates UTC solar events, then shifts them to local time.
Professional note
Master’s Tip: check the timezone offset first. A correct latitude and longitude still gives the wrong local clock time if daylight saving or UTC offset is wrong.
Regional and unit assumptions
Standard or basis: simplified NOAA-style solar calculation with manual timezone offset.
Assumptions and limitations
- Uses a simplified solar-position approximation suitable for general planning.
- Uses official zenith 90.833 degrees for ordinary sunrise/sunset including refraction.
- Timezone offset is entered manually and does not apply daylight-saving rules automatically.
- Polar day/night edge cases may need specialist ephemeris data.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Approximate solar event times are calculated from day of year, longitude hour, solar mean anomaly, true longitude, right ascension, declination and the sunrise/sunset hour angle.
Standard or basis
Standard or basis: simplified NOAA-style solar calculation with manual timezone offset.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: check the timezone offset first. A correct latitude and longitude still gives the wrong local clock time if daylight saving or UTC offset is wrong.
Related calculators
Questions
Is this exact enough for navigation?
No. It is a planning calculator. Use official ephemeris or navigation tools for safety-critical work.
Why enter UTC offset manually?
Manual offset makes the arithmetic visible and avoids pretending that every daylight-saving rule is embedded.
Does it handle polar day?
The page flags polar day/night edge cases when the simple sunrise/sunset hour angle is outside range.
Calculation note
Sunrise and sunset are local events: date, latitude, longitude and the chosen clock offset all matter.