Sunrise & Sunset Calculator

The Sunrise & Sunset Calculator works out the exact times the Sun rises and sets for any location and date on Earth, along with solar noon, day length, every twilight phase, and the photographer's golden hour and blue hour. It also shows an animated sun-path arc, a 24-hour day/night sky ribbon, and how much the day length is changing from one day to the next.

How Sunrise and Sunset Are Calculated

Sunrise and sunset depend on where the Sun sits in the sky, which changes with your latitude, your longitude, and the date. The calculation follows the widely used NOAA solar position algorithm in three short steps.

Here \(\varphi\) is your latitude, \(\lambda\) your longitude, \(\delta\) the Sun's declination, \(E\) the equation of time, and \(\Delta_{tz}\) the UTC offset in minutes. The Sun's center is placed \(0.833^\circ\) below the horizon at sunrise and sunset to account for atmospheric refraction (about \(0.567^\circ\)) and the Sun's apparent radius (about \(0.267^\circ\)). The result is accurate to roughly one minute.

Twilight Phases Explained

After the Sun drops below the horizon the sky does not go dark instantly. Astronomers divide this fading light into three phases, defined by how far the Sun is below the horizon.

Golden Hour and Blue Hour

Photographers prize the soft, warm light around sunrise and sunset. The golden hour is when the Sun is low in the sky, roughly between \(-4^\circ\) and \(+6^\circ\), bathing everything in warm, directional light with long shadows. The blue hour is the period just before the golden hour in the morning and just after it in the evening, when the Sun is about \(4^\circ\) to \(6^\circ\) below the horizon and the sky takes on a deep, even blue. This calculator gives you all four windows — morning and evening — so you can plan a shoot to the minute.

Why Day Length Changes Faster in Spring and Autumn

The number of daylight minutes you gain or lose each day is not constant. Near the equinoxes (around March 20 and September 22) day length changes fastest — by several minutes per day at mid latitudes. Near the solstices (around June 21 and December 21) it barely changes at all, which is why we get long stretches of similar-length days in midsummer and midwinter. The calculator shows the exact change compared with the previous day, so you can watch this seasonal rhythm.

Midnight Sun and Polar Night

Above the Arctic Circle (about \(66.5^\circ\) N) and below the Antarctic Circle, the Sun can stay above the horizon for a full 24 hours around the summer solstice — the famous Midnight Sun — or remain below the horizon all day around the winter solstice, known as polar night. When you choose a high-latitude city such as Tromsø or Reykjavík near a solstice, the calculator detects these situations and reports a 24-hour or 0-hour day instead of a sunrise time. Try it to see how dramatically day length swings as you move toward the poles.

How to Use This Calculator

1. Choose a location: Pick a city from the dropdown, or enter your own latitude and longitude in decimal degrees (negative for South and West).
2. Set the date and time zone: Choose a date and select the UTC offset for your location. Add one hour if daylight saving time is in effect.
3. Click Calculate: The tool computes sunrise, sunset, solar noon, and day length instantly.
4. Explore the results: Study the sun-path arc, the 24-hour sky ribbon, all twilight phases, the golden and blue hours, and how the day length is changing.

Frequently Asked Questions

How are sunrise and sunset times calculated?

Sunrise and sunset are found from the Sun's position in the sky. Using the date we compute the Sun's declination and the equation of time, then the hour angle at which the Sun's center is 0.833° below the horizon (which allows for atmospheric refraction and the Sun's radius). Sunrise is solar noon minus that hour angle and sunset is solar noon plus it.

What is the difference between civil, nautical, and astronomical twilight?

Twilight is split by how far the Sun is below the horizon. Civil twilight is 0° to 6° below and is bright enough for most outdoor activity. Nautical twilight is 6° to 12° below, when the horizon is still visible at sea. Astronomical twilight is 12° to 18° below; beyond 18° the sky is fully dark.

What are the golden hour and blue hour?

The golden hour is the period soon after sunrise or before sunset when the Sun is low (about −4° to +6°) and the light is warm and soft. The blue hour is the slightly darker period before the golden hour in the morning and after it in the evening, when the Sun is roughly 4° to 6° below the horizon and the sky turns deep blue.

Why does day length change by a different amount each day?

The rate at which day length changes depends on your latitude and the time of year. Near the equinoxes the day length changes fastest, by several minutes per day at mid latitudes, while near the solstices it barely changes at all. This calculator shows exactly how many seconds the day is gaining or losing compared with the previous day.

What is the Midnight Sun and polar night?

Above the Arctic and Antarctic circles the Sun can stay above the horizon for a full 24 hours in summer (the Midnight Sun) or stay below it all day in winter (polar night). When you choose a high-latitude location near a solstice, this calculator detects these cases and reports a 24-hour or 0-hour day length instead of a sunrise time.

Does this calculator account for daylight saving time?

The calculator uses the UTC offset you select, which represents standard time. If daylight saving time is in effect for your chosen date, add one hour to the offset so the displayed clock times match your local clock.

Additional Resources

• Sunrise - Wikipedia
• Twilight - Wikipedia
• NOAA Solar Calculator