The Sunrise Sunset Calculator finds the sunrise, sunset, solar noon, and total day length for any latitude and longitude on any date, using the same NOAA solar position equations that meteorological agencies rely on. Enter a location as decimal coordinates and a date, and the calculator returns sunrise and sunset times alongside civil, nautical, and astronomical twilight windows, golden hour, and blue hour, all corrected for time zone and daylight saving.
Find sunrise and sunset for any location
A location's sunrise and sunset times depend on latitude, longitude, the date, and the local time zone, since the sun's apparent path across the sky changes continuously through the year and differs at every latitude.
The Sunrise Sunset Calculator takes all four inputs together and returns times already converted to local clock time, including a daylight saving adjustment when the selected date falls within a zone's daylight saving period.
Latitude determines how much the day length varies through the year, with the effect strongest near the poles and negligible near the equator. Longitude, combined with the time zone, determines how far a location's solar noon sits from its clock noon, since time zones cover a range of longitudes but only one can align exactly with the zone's reference meridian.
Enter latitude and longitude correctly
Coordinates are entered as decimal degrees, with north as positive and south as negative for latitude, and east as positive and west as negative for longitude. The Sunrise Sunset Calculator accepts this format directly from a GPS reading or a map service, without needing conversion from degrees-minutes-seconds first.
Boston, Massachusetts sits at approximately 42.36 degrees north and 71.06 degrees west, entered as 42.36 for latitude and -71.06 for longitude. A common data-entry mistake is leaving off the negative sign on a western longitude or a southern latitude, which places the calculation on the opposite side of the globe and returns times that make no sense for the intended location.
Read the three types of twilight
Twilight is graded by how far the sun's center sits below the horizon after sunset or before sunrise, and the Sunrise Sunset Calculator reports three distinct thresholds rather than a single generic twilight time.
Civil twilight ends when the sun reaches 6 degrees below the horizon, the point at which outdoor activity without artificial light becomes difficult; this is what most people mean by dawn or dusk.
Nautical twilight ends at 12 degrees below the horizon, historically the limit at which a ship's horizon remained visible enough for star navigation. Astronomical twilight ends at 18 degrees below the horizon, the point at which the sun no longer brightens the sky enough to interfere with astronomical observation. Each threshold produces its own dawn and dusk time, distinct from the sunrise and sunset time itself.
Understand solar noon and day length
Solar noon is the moment the sun reaches its highest point in the sky for that day and location, which rarely coincides exactly with 12:00 on a local clock.
The offset between solar noon and clock noon comes from two sources: the location's position within its time zone, and the equation of time, a small seasonal variation in the sun's apparent speed caused by Earth's elliptical orbit and axial tilt.
Day length is the duration from sunrise to sunset, which the Sunrise Sunset Calculator computes directly from the two times rather than as a separate calculation. It varies smoothly through the year at any latitude outside the tropics, reaching a maximum at the summer solstice and a minimum at the winter solstice.
Find sunrise for Boston on 21 June
For Boston, at 42.36 degrees north and 71.06 degrees west, on 21 June, the summer solstice, sunrise occurs at approximately 5:07 AM and sunset at approximately 8:24 PM local daylight time, a day length of about 15 hours 17 minutes.
1. Establish the date's solar declination. On the summer solstice, the sun's declination reaches its maximum for the year, close to 23.4 degrees north, which is what produces the longest day of the year in the Northern Hemisphere.
2. Compute the hour angle for Boston's latitude. At 42.36 degrees north with that declination, the sun spends more than 15 hours above the horizon, since higher latitudes see a larger swing in day length at the solstices than latitudes closer to the equator.
3. Convert the hour angle to clock time, correcting for Boston's longitude within the Eastern time zone and the equation of time for that date, then applying the daylight saving offset in effect in June.
4. Read the result. Sunrise at 5:07 AM and sunset at 8:24 PM together span 15 hours 17 minutes, the longest day of the year at this location.
Plan golden hour and blue hour
Golden hour is the period when the sun sits between 4 degrees below and 6 degrees above the horizon, prized by photographers for warm, low-angle light with soft shadows. Blue hour follows or precedes it, when the sun sits between 6 and 4 degrees below the horizon, producing the deep blue sky tone visible just after sunset or before sunrise.
The Sunrise Sunset Calculator computes both windows directly from the sun's elevation angle rather than as a fixed offset from sunrise or sunset, since the rate at which the sun's angle changes varies by latitude and season, making golden hour noticeably longer at high latitudes in summer than near the equator at any time of year.
Handle polar day and polar night
Above the Arctic Circle and below the Antarctic Circle, there are days each year when the sun never sets and days when it never rises, a condition the underlying solar equation reflects as a value outside the valid range for the hour angle calculation.
The Sunrise Sunset Calculator detects this condition directly and reports "Polar day, the sun does not set" or "Polar night, the sun does not rise" rather than returning an invalid or nonsensical time.
This handling matters because the raw trigonometric formula for the hour angle produces a value with no valid solution whenever the sun's declination and the location's latitude combine to keep the sun entirely above or entirely below the horizon for the full day. Returning a clear polar-condition message instead of an error or a meaningless number is a deliberate design choice this calculator makes.
Understand the accuracy of these times
Sunrise and sunset times from this calculator are accurate to within about one minute for latitudes under 65 degrees, based on the NOAA solar position equations and a standard atmospheric refraction correction of 0.833 degrees, which accounts for both the bending of light near the horizon and the apparent size of the sun's disk.
Actual atmospheric refraction varies with local temperature and air pressure, and unusual weather conditions can shift the observed moment of sunrise or sunset by more than the calculated figure suggests. Near the poles, where the sun's path crosses the horizon at a shallow angle, small differences in refraction can shift the calculated time by several minutes, which is why the one-minute accuracy claim is limited to latitudes under 65 degrees rather than stated universally.
Frequently asked questions
How do I find sunrise and sunset times for my location?
Enter the location's latitude and longitude in decimal degrees, along with a date, into the Sunrise Sunset Calculator. It returns sunrise, sunset, solar noon, and day length, converted to local clock time with daylight saving applied automatically when relevant.
What is the difference between civil, nautical, and astronomical twilight?
The three types differ by how far the sun sits below the horizon: 6 degrees for civil twilight, 12 degrees for nautical twilight, and 18 degrees for astronomical twilight. Civil twilight is the closest to what most people mean by dawn or dusk; astronomical twilight is the point at which the sky is dark enough for observation.
Why is solar noon not the same as 12:00 on the clock?
Solar noon shifts away from clock noon because of a location's position within its time zone and the equation of time, a seasonal variation in the sun's apparent speed caused by Earth's elliptical orbit and axial tilt. The offset can be more than 30 minutes in either direction depending on the date and location.
What happens at the North Pole in summer?
Locations above the Arctic Circle experience polar day around the summer solstice, when the sun does not set for one or more consecutive days. The Sunrise Sunset Calculator reports this explicitly rather than returning an invalid sunrise or sunset time.
How accurate are the sunrise and sunset times?
Times are accurate to within about one minute for latitudes under 65 degrees, using the same solar position equations and refraction correction that meteorological agencies use. Local atmospheric conditions can shift the actual observed moment slightly beyond the calculated figure.
What is golden hour?
Golden hour is the period when the sun sits between 4 degrees below and 6 degrees above the horizon, producing warm, low-angle light favored in photography. Its length varies by latitude and season, running noticeably longer at high latitudes in summer.
Does the calculator account for daylight saving time?
Yes. Sunrise, sunset, and all twilight times are converted to the local clock time in effect on the selected date, including any daylight saving adjustment for locations that observe it.
Why do sunrise times differ from a printed almanac?
Small differences usually come from a different refraction assumption or a slightly different set of coordinates for the named location, since a city's coordinates can be entered as its center, its airport, or another reference point, each producing a very slightly different time.
Summary
The Sunrise Sunset Calculator uses NOAA solar position equations to compute sunrise, sunset, solar noon, and day length for any latitude, longitude, and date, correcting for time zone and daylight saving automatically. Civil, nautical, and astronomical twilight, along with golden hour and blue hour, are computed from the sun's actual elevation angle rather than a fixed offset.
Locations inside the Arctic or Antarctic Circle receive an explicit polar day or polar night message instead of an invalid result, and times are accurate to within about one minute for latitudes under 65 degrees.