Sunrise Calculator
Approximate local-solar-time sunrise
How to Use This Calculator
Enter latitude and day of year. This tool returns an approximate sunrise in local solar time (not clock time).
Formula
H₀ = arccos(-tan φ · tan δ)
Sunrise ≈ 12 − (H₀·180/π) / 15
Frequently Asked Questions
Why not clock time?
Converting to clock time needs longitude, timezone, and equation of time. This tool gives local solar time.