What is the golden hour in photography?

Golden hour refers to the roughly one-hour period just after sunrise and just before sunset when the sun is low in the sky. At this angle sunlight travels through a greater thickness of atmosphere, scattering blue wavelengths and leaving warm orange and amber tones. Shadows are long and soft, contrast is gentle, and skin tones look flattering — which is why portrait and landscape photographers prize it above all other light.

How is the golden hour defined technically?

This calculator defines it as the window when the sun's altitude is between -4° and +6° above the horizon. Below -4° the sky is still dark (astronomical twilight) and the warm glow is absent; above +6° the sun is high enough that the warming effect fades and light becomes harsher. The morning window runs from roughly -4° (rising) to +6°; the evening window from +6° (setting) back to -4°.

What is the blue hour?

Blue hour falls just before morning golden hour and just after evening golden hour, when the sun is between -6° and -4° altitude. The sun is below the horizon, so direct sunlight is absent, but scattered light in the upper atmosphere creates a pure cool-blue sky. It is ideal for urban photography, cityscapes, and any shot where you want ambient sky light without a strong light source.

How accurate are the times?

The algorithm is based on the NOAA Solar Calculator (Jean Meeus "Astronomical Algorithms"). For latitudes between -65° and +65° it is accurate to within about one minute. At extreme latitudes near the poles accuracy decreases, and the calculator will flag polar-day or polar-night conditions automatically.

Does the golden hour last exactly one hour?

No. Duration varies significantly with latitude, season, and the angle at which the sun rises or sets. Near the equator the sun rises and sets steeply, so golden hour can be as short as 20-30 minutes. At high latitudes in summer the sun moves nearly parallel to the horizon and golden hour can last two hours or more. Use the duration column in the results table to see the exact length for your location and date.

Why do I need to enter a UTC offset?

The solar formula works in Universal Time (UTC). Entering your local UTC offset converts all results to your local clock time so you can set your alarm correctly. If you prefer raw UTC simply leave the offset at 0.

Golden Hour Calculator

The golden hour calculator tells you the precise start and end times for the morning and evening golden-hour windows, the blue-hour windows, and the key solar events (sunrise, solar noon, sunset) for any location on Earth on any date. Every calculation runs entirely in your browser — no data is sent anywhere.

How it works

The underlying engine is a JavaScript implementation of the NOAA Solar Calculator algorithm, which is itself derived from Jean Meeus’s Astronomical Algorithms. The core of the calculation is the solar altitude formula:

sin(altitude) = sin(lat) × sin(dec) + cos(lat) × cos(dec) × cos(H)

where lat is your latitude, dec is the sun’s declination on the date in question, and H is the solar hour angle (how far the sun is from local solar noon). Rearranging for H gives:

cos(H) = (sin(altitude) − sin(lat) × sin(dec)) / (cos(lat) × cos(dec))

For each altitude boundary — -6°, -4°, +6° — the calculator solves this equation and converts the resulting hour angle back to a clock time using the equation of time (the difference between mean solar time and apparent solar time) and your longitude. Standard sunrise and sunset use an altitude of -0.833° to account for atmospheric refraction and the apparent radius of the solar disc.

The four photographic windows are:

Window	Sun altitude	Character
Blue hour (morning)	-6° to -4°	Deep blue sky, no direct sunlight
Golden hour (morning)	-4° to +6°	Warm amber, long soft shadows
Golden hour (evening)	+6° to -4°	Same as morning, reversed
Blue hour (evening)	-4° to -6°	Cool blue, city lights balance sky

Worked example

Location: London (51.5074 °N, -0.1278 °E), Date: 21 June (summer solstice), UTC offset: +1 (BST)

On the summer solstice the sun rises very early and climbs steeply — but because London is at 51.5°N the arc is still low enough to give generous golden-hour windows:

Morning blue hour: approx. 03:45 – 04:02 (17 min)
Morning golden hour: approx. 04:02 – 05:07 (65 min)
Sunrise: approx. 04:43
Sunset: approx. 21:21
Evening golden hour: approx. 20:16 – 21:37 (81 min)
Evening blue hour: approx. 21:37 – 21:55 (18 min)

Compare with 21 December (winter solstice): the sun rises far later and only reaches about 15° at noon, making every golden-hour window shorter and the quality of light remarkable throughout the low-sun winter day.

Formula note

The key inputs derived during calculation are:

Solar declination — the sun’s latitude (varies from -23.44° at winter solstice to +23.44° at summer solstice).
Equation of time — a correction of up to ±16 minutes for the eccentricity of Earth’s orbit and the tilt of the ecliptic.
Solar noon in UT = (720 − 4 × longitude − equationOfTime) / 60.
Hour angle for each altitude boundary, solved from the altitude formula above.
Rising time = solarNoon − hourAngle / 15; setting time = solarNoon + hourAngle / 15.

The /15 factor converts degrees of arc to hours of time (Earth rotates 15° per hour).