Sunrise Sunset Calculator
Approximate sunrise/sunset times in local solar time (LST) and daylight hours.
How to Use This Calculator
1
Enter latitude and day
Latitude positive north, negative south. Use the calendar day number (1–366).
2
Read LST times
Times are in local solar time (sun at noon at 12:00). To get clock time, adjust for longitude/time zone and equation of time.
Formula
cosH = (sin h₀ − sinφ sinδ) / (cosφ cosδ), day = 2H/15
Use h₀ = −0.833° to account for refraction and solar radius. This is an approximation.
Frequently Asked Questions
Why are results in LST?
Local solar time is tied to the Sun’s position. Converting to local clock time requires longitude, time zone, and equation of time.
Is this valid near the poles?
At high latitudes polar day/night occurs; the tool reports 24 h or 0 h daylight accordingly.