Golden Hour Calculator

Outdoor light changes fastest near the edges of the day. When the sun sits low, its path through the atmosphere is longer and its direction is more sideways than overhead. Faces gain shape, buildings throw long shadows, textures stand out, and skies can move from pale blue to warm orange or deep blue in a short span. Portrait sessions, landscapes, city viewpoints, travel routes, and video b-roll often start from the light window because the scene changes faster than most camera settings.

Golden hour and blue hour are planning names, not strict astronomical standards. Golden hour usually refers to the period around sunrise or sunset when the sun is just above the horizon and the light is warmer, softer, and easier to shape. Blue hour sits beside it while the sun is below the horizon and the sky may still hold enough color for city lights, water, silhouettes, and tripod scenes. The names describe a useful look, not a promise that every sky will turn gold or blue.

The same clock time cannot be reused from one location or season to another. Latitude controls how steeply the sun crosses the horizon, longitude shifts solar noon against the clock, and the UTC offset turns solar minutes into local labels. Seasonal declination changes the arc again, so one city can have a brief summer sunrise, a drawn-out winter twilight, or a high-latitude date where a familiar boundary is never crossed.

Solar altitude

The sun's angle above or below the horizon. This is the main quantity behind golden-hour and blue-hour timing.

Solar azimuth

The compass direction of the sun, measured clockwise from north. It helps match low light with the direction a subject or street faces.

Civil twilight

The bright twilight range near the horizon, commonly tied to the sun being down to about 6 degrees below the horizon.

Solar geometry gives the planning window; the scene decides the usable light. Mountains, buildings, tree cover, haze, smoke, cloud, elevation, coastal refraction, and a blocked horizon can move the practical start or end earlier than the clean altitude crossing. For scouting and call sheets, the window marks when to be ready, while field conditions decide the final shot order.

How to Use This Tool:

Start with a trustworthy location and date, then choose the planning window that matches the shoot.

1. Choose Location source. IP Geolocation gives an approximate starting point from the current public network. City Search sends the place text to OpenStreetMap Nominatim and uses the selected match. Browser GPS asks the browser for device location. Manual Coordinates is best when you already have the exact shooting spot.
2. Confirm Shoot location, Shoot date, and UTC offset. The coordinates drive the solar geometry, while the offset turns solar minutes into local clock labels. Check daylight saving time for the shoot date before sharing the schedule.
3. Set Planning focus to evening, morning, or both. The summary emphasizes that choice, but Window Plan still lists morning blue hour, morning golden hour, evening golden hour, and evening blue hour when those crossings exist.
4. Pick a Shoot profile and adjust Arrival buffer. The profile changes the practical cue for portraits, landscapes, city scenes, video b-roll, or travel scouting; the buffer moves the ready-by time before the selected golden-hour start.
5. Open Advanced only when the defaults do not match the way you plan light. You can switch clock format, raise or lower Golden upper angle, widen or narrow Blue outer angle, and move the Blue/golden handoff.
6. Fix any warning before using the result. Latitude must be between -90 and +90 degrees, longitude between -180 and +180 degrees, UTC offset between -12 and +14 hours, blue outer angle below the handoff, and golden upper angle above the handoff.
7. Read Window Plan for the schedule, Shoot Brief for ready-by guidance, Solar Markers for sunrise, sunset, and threshold times, Sun Direction for azimuth, and Light Curve for how quickly the sun moves through the selected bands.

Interpreting Results:

The summary is the first planning check. It shows the selected morning, evening, or full-day golden-hour target, the location label, the total golden-light duration for that focus, and the ready-by time after the arrival buffer is applied. If it says No standard golden-hour crossing, the selected date and location do not pass through the configured low-angle boundary in the usual way.

Window Plan gives the usable schedule in rows. Start and end times are local clock labels based on the UTC offset you entered. Duration tells you how long the altitude band lasts. A short blue hour or golden hour usually means the sun is crossing the horizon steeply, so setup delays matter more. A long twilight or polar caution means the word "hour" is only a rough label.

• Shoot Brief: use Arrival time as the setup target, not the moment to start unloading gear.
• Solar Markers: compare Sunrise, Sunset, Solar noon, and the blue/golden boundaries when you need exact call-sheet notes.
• Sun Direction: read azimuth as a compass bearing from north. East is about 90 degrees, south is about 180 degrees, and west is about 270 degrees.
• Light Curve: use the shape of the curve to judge whether light changes slowly or drops quickly through the low-angle bands.
• False confidence check: a clean table does not prove the view is clear. Verify UTC offset, coordinates, weather, horizon blockage, access, and the direction your subject faces.

Technical Details:

Golden-hour timing is a solar-altitude crossing problem. Solar altitude is 0 degrees at the geometric horizon, positive above it, and negative below it. A chosen altitude boundary becomes a time when the sun's apparent path reaches that height on the morning side or evening side of solar noon.

The date supplies the day-of-year terms that estimate equation of time and solar declination. Equation of time shifts apparent solar time away from uniform clock time. Solar declination is the sun's apparent north-south position over the year. Latitude, longitude, and UTC offset then determine local solar noon and the hour angle needed to reach each altitude boundary.

The same crossing method is reused for blue hour, golden hour, sunrise, sunset, solar markers, and sun-direction rows. When the requested altitude cannot be reached on that date at that latitude, the crossing is absent rather than forced into a normal-looking schedule.

Formula Core:

The same crossing equation is used for the golden upper boundary, the blue/golden handoff, the blue outer boundary, and the apparent sunrise or sunset boundary. Angles are evaluated in radians for the trigonometric functions, while the displayed hour angle and times are converted back to degrees and minutes.

For London on 2026-06-21 with UTC+1, latitude 51.5074 and longitude -0.1278, the +6 degree altitude crossing gives an hour angle of about 111.25 degrees. Multiplying by 4 gives about 445 minutes from solar noon, so the evening upper golden boundary appears around 20:27 and the matching morning boundary around 05:37 with the default settings.

Window Boundaries:

Boundary labels are inclusive at the handoff and golden upper angle. Altitudes from the handoff through the golden upper angle are labeled Golden hour. Altitudes from the blue outer angle up to, but not including, the handoff are labeled Blue hour. Higher values are daylight, and lower values are night or darker twilight.

Validation and Edge Cases:

Displayed times are rounded to minute-level planning labels. The light curve samples solar altitude across the local day, while the table rows use calculated boundary crossings. Small differences from an observatory-grade ephemeris can occur because the model is intended for field planning and does not account for local terrain, actual refraction, weather, skyline height, or a photographer's elevation above the surrounding ground.

Limitations, Privacy, and Accuracy Notes:

Golden-hour output should not be used as an official sunrise/sunset source or as a safety-critical navigation aid. It is a photography planning estimate. A few minutes can matter when a ridge, building, cloud bank, or coastal horizon blocks the sun, so field checks still matter even when the solar calculation is internally consistent.

• Time zones: the UTC offset is manual. A daylight saving mistake shifts every local clock label by an hour.
• IP Geolocation: public-IP lookup is approximate and can reflect an ISP, VPN, proxy, carrier gateway, or city center rather than the actual camera position.
• City Search: submitted place text is sent to OpenStreetMap Nominatim, and the selected result may describe a city center rather than the exact foreground or viewpoint.
• Browser GPS: choosing that source starts a browser permission request. If it is denied or unavailable, use City Search or Manual Coordinates.
• Manual Coordinates: exact coordinates improve timing, but they do not describe horizon blockage, weather, access, or reflected light.

Worked Examples:

London summer portrait session. With London set to 2026-06-21 and UTC+1, the default evening golden hour runs from about 20:27 to 21:49. With a 25 minute Arrival buffer, Shoot Brief gives a ready-by time around 20:02. Sun Direction places the start near 301 degrees WNW, so a west-facing location is more likely to see direct low sun than an east-facing wall.

Singapore equinox scouting. With Singapore on 2026-03-20 and UTC+8, the default evening golden hour is about 18:49 to 19:29, while evening blue hour is about 19:29 to 19:37. Light Curve drops steeply through the horizon bands, so the Arrival time matters more than the label "hour" suggests.

Reykjavik high-latitude check. Reykjavik on 2026-06-21 can show missing blue-hour crossings and unusual low-light behavior because the sun does not pass through every configured boundary cleanly. When Window Plan says No crossing, use Light Curve, Solar Markers, and the latitude badge to choose a usable low-sun period instead of forcing a normal golden-hour schedule.

Correction after a warning. If a custom threshold change makes Blue outer angle equal to or higher than Blue/golden handoff, the calculation waits for a valid order. Put the blue outer value below the handoff, or move the handoff closer to zero, then recheck Window Plan before copying times into a call sheet.

FAQ:

Glossary:

Golden hour

The low-sun planning band around sunrise or sunset, using the configured handoff and upper altitude boundaries.

Blue hour

The nearby twilight band below the golden-hour handoff, often useful for skyline color, city lights, silhouettes, water, and reflections.

Solar altitude

The sun's angle above or below the horizon. Positive values are above the horizon, and negative values are below it.

Solar azimuth

The sun's compass bearing measured clockwise from north.

Solar noon

The time when the sun reaches its highest altitude for the selected date and longitude.

Equation of time

The date-dependent difference between apparent solar time and mean clock time.

Solar declination

The sun's apparent north-south position over the year, which drives seasonal changes in sun height.

UTC offset

The number of hours added to or subtracted from UTC to label the calculated crossings in local clock time.

References:

• General Solar Position Calculations, NOAA Global Monitoring Laboratory.
• The Golden Hour - When Sunlight Turns Magical, timeanddate.com.
• Civil Twilight - Civil Dawn and Dusk, timeanddate.com.
• Nominatim Usage Policy, OpenStreetMap Foundation.
• Geolocation API, MDN Web Docs, March 10, 2026.
• Geolocation accuracy, MaxMind.