Golden Hour Calculator
Compute morning/evening golden and blue hour windows, plus civil/nautical/astronomical twilight.
Overview
The Golden Hour Calculator pinpoints the morning and evening windows when the Sun sits low enough to give photographs that warm, soft, directional light photographers prize. Enter a latitude, longitude, and date and you get the start and end of both golden hours, both blue hours, and the three twilight phases (civil, nautical, astronomical).
Useful for landscape and portrait photographers planning shoots, videographers chasing magic-hour exteriors, drone operators scouting flight windows, real-estate listing photographers, and anyone who wants the sky a particular shade of pink at a specific location.
How it works
The Sun's altitude is computed using the NOAA solar position algorithm, which is accurate to within about a minute for any date and any earthbound location. Golden hour is conventionally defined as when the solar altitude is between −4° and +6° above the horizon; blue hour spans roughly −6° to −4°, where the sky is still bright but the Sun is below the horizon.
Civil twilight ends at −6° (rough rule of thumb: you can still read a newspaper outside), nautical twilight at −12° (the horizon is no longer visible at sea), and astronomical twilight at −18° (the sky is fully dark and faint stars are detectable). All four threshold angles are standard across astronomy and aviation tables.
Examples
Reykjavík (64.1°N) on June 21
→ Sun never drops below −6°; golden hour lasts effectively all night
San Francisco (37.8°N) on March 20 (equinox)
→ Morning golden: 06:50–07:32
→ Evening golden: 19:01–19:43
→ Evening blue: 19:43–20:01
Sydney (33.9°S) on Dec 21
→ Morning golden: 05:42–06:23
→ Evening golden: 19:47–20:28
FAQ
What altitude defines golden hour?
By the most common convention, the Sun sits between −4° (just below the horizon) and +6° (still low in the sky). Some photographers use a stricter 0° to +6° window.
What is the difference between golden and blue hour?
Golden hour is when the Sun is just above or below the horizon and the light is warm orange. Blue hour follows golden hour after sunset (or precedes it before sunrise) and lasts while the Sun is roughly 4° to 6° below the horizon and the sky takes a cool blue cast.
Why is there no golden hour near the poles in summer?
Above the polar circles the Sun can stay below 6° altitude for weeks (or above −6° for weeks), so the threshold-based definition breaks down and the magic light effectively lasts all "night."
Does atmospheric refraction affect the times?
Yes — refraction lifts the Sun's apparent position by about 34 arc-minutes near the horizon. The calculation includes a standard refraction term, so the times match what you observe in normal clear-weather conditions.
How accurate is the result?
Within about one minute for any date and location at sea level. Mountain altitudes shift sunrise and sunset by a few seconds per kilometre of elevation, which is below the rounding resolution shown.