Sun Calculator

For any date and any place on Earth, this calculator returns sunrise, sunset, solar noon and day length from four inputs: date, latitude, longitude and UTC offset. It uses a simplified solar model, so treat its times as planning figures good to within a few minutes for most mid-latitude places, not as almanac-grade predictions. The limits of that model are stated plainly below, and every number in the worked example is the tool’s own output.

Quick Answer

How to use the sun calculator

Four inputs, one button, five outputs. The results stay hidden until you calculate.

1. Pick the date. The calculator is pre-filled with June 21, 2026, the worked example below. Any date works, including leap-day dates.
2. Enter latitude and longitude. North and east are positive, south and west are negative. A sign error here is the most common mistake: New York is latitude 40.71, longitude minus 74.01, not plus.
3. Pick the UTC offset in force on that date. If the place observes daylight saving, pick the daylight offset for summer dates and the standard offset for winter dates. Karachi stays on UTC+5 all year, so the same choice works in June and December.
4. Click Calculate. Sunrise, sunset, day length, solar noon and day of year appear in the results box. Copy or share them with the buttons inside the box.

Blank dates, blank coordinates or non-numeric coordinates are rejected with the message "Please enter valid values" and no results are shown. The tool does not check that a latitude falls inside the real range of minus 90 to plus 90, so a typed value beyond that range still produces numbers that mean nothing: keep latitudes inside that range.

The formula: declination, hour angle, solar noon

Three steps turn a date and a place into clock times. First, the sun's declination, the angle of the sun above or below the celestial equator, comes from Cooper's approximation, which treats the Earth's tilt as 23.45 degrees and the orbit as a simple sine wave over the day of year.

Second, the hour angle is half the sun's arc across the sky, found from latitude and declination. When the cosine of the hour angle falls outside minus 1 to plus 1, the sun never crosses the horizon that day: that is the polar case, handled in the section below. Third, solar noon follows from longitude alone, because the Earth turns 15 degrees per hour: a place 67 degrees east of Greenwich reaches solar noon 67 ÷ 15, about 4.47 hours, before Greenwich does, which is why Karachi's solar noon in UTC is about 07:32 and 12:32 on the local clock at UTC+5. Sunrise and sunset sit symmetrically around that noon, which is exactly why this model cannot reproduce the small real-world asymmetry caused by the equation of time. The fuller method used by the NOAA solar calculator adds the equation of time, a refraction-corrected horizon of 90.833 degrees and a second iteration at the event time, and lands within a minute or two of published almanacs for most mid-latitude places.

Worked example: Karachi on the June solstice

Karachi sits at latitude 24.8607, longitude 67.0011, on Pakistan Standard Time, UTC+5 all year. June 21, 2026 is day 172 of the year. Running the calculator gives the figures in the Quick Answer box, and the arithmetic underneath is short enough to check by hand.

The old version of this page printed sunrise 5:43, sunset 7:24 PM and day length 13 hours 41 minutes for this same example. None of those three figures is what the tool produces: the tool gives 05:46, 19:18 and 13h 33m. The old figures look like almanac times pasted beside a tool that never computed them, and they are not repeated here. The remaining gap between the tool and an almanac, a few minutes, is the price of the simplifications disclosed above, and it is the reason this page never calls the results exact.

Every row above is a real run of this calculator. Note the southern hemisphere flip: Sydney's June day is its shortest, under ten hours, while London's runs past sixteen. The equator row is the model's cleanest case, exactly twelve hours, because declination drops out of the hour angle at latitude zero.

Karachi through the year: day length by month

Day length in Karachi swings by about three hours between winter and summer. The table below runs the calculator for the 15th of each month in 2026 at the same coordinates and offset, so the seasonal curve is visible without retyping anything.

Solar noon never moves in this table: it stays 12:32 all year, because solar noon in this model depends only on longitude and offset, never on the date. In reality solar noon drifts by up to about 16 minutes through the year as the equation of time swings, which is the single biggest reason this tool's times differ from an almanac. Gardeners planning around this table should read it as a seasonal shape, not a daily timetable.

Reading the results: solar noon, the DST trap and the polar circles

Solar noon is the moment the sun crosses your meridian, its highest point for the day, and it is not the same as 12:00 on the clock. Two things move it: longitude within the time zone, and the equation of time, which this tool omits. Karachi at longitude 67 sits about 8 degrees west of the UTC+5 central meridian at 75 degrees east, so its solar noon falls about 32 minutes after 12:00 UTC would suggest, landing at 12:32. A place east of its zone's central meridian gets an earlier solar noon, and a place near the zone's western edge gets a later one. Photographers chasing golden hour should anchor on sunrise and sunset from this tool, then check a full almanac for the exact minute, since golden hour itself sits in the hour after sunrise and before sunset and inherits the same few-minute uncertainty.

The daylight saving trap is the easiest way to get a wrong answer out of a right tool. This calculator's offset list is fixed: it carries standard and daylight variants as separate entries and never switches between them for you. Picking UTC-5 for New York in July returns times one hour early, because New York in July runs on UTC-4. The same trap catches London in summer (UTC+1, not UTC 0) and Sydney in summer (UTC+11, not UTC+10). If you are unsure which offset applies on your date, check it with the time zone calculator before running this one, and remember that the offset must match the date, not today's offset.

Above the Arctic and Antarctic circles, the sun stops rising or setting for part of the year. The previous version of this tool clamped the hour angle but then printed a sunrise and sunset both equal to solar noon with a day length of 0h 0m, even on a midnight-sun day when the true day length is 24 hours. This version fixes that: a polar day reports no sunrise and no sunset with 24h 0m, and a polar night reports no sunrise and no sunset with 0h 0m. At latitude 78, longitude 15, UTC+2, June 21 gives midnight sun and December 21 gives polar night, both with solar noon at 13:00. If you need twilight times for polar work, this tool does not compute them at all: use a full solar position tool instead.

What competing sun calculators miss

Most sunrise and sunset tools fall into two camps, and each leaves a different gap:

• Full NOAA-method tools (OnlyCalculators sunrise-sunset and daylight pages, HeroYears): the strongest rivals. They run the Meeus-based NOAA equations with equation of time and refraction-corrected horizons, add civil, nautical and astronomical twilight, and in one case a month-by-month day-length chart. Their weakness is opacity about method on the page itself for casual users, and none of them states its accuracy limit as plainly as it should: "within one minute" claims sit beside polar-zone caveats that quietly undo them.
• Map-pin tools (GPS Coordinates Finder): pick a point on a map and get sunrise, sunset, solar noon, golden hours, all three twilights and a daylight timeline in the location's own time zone, with daylight saving handled automatically. The gap is the opposite of ours: the map is the input, so a user who already knows coordinates gains nothing, and the page's own sample output shows a solar noon of 10:07 for a Mediterranean pin without explaining why noon sits two hours from 12:00.
• Formula pages (Firgelli daylight calculator, TrueGeometry solar calculation): they publish the declination, hour-angle and day-length equations openly, which is genuinely useful for students, but their tools take day-of-year numbers instead of dates, and TrueGeometry's own sample table shows a day length of 0.139 hours for a June day at latitude 34, which is plainly wrong output from a mismatched formula. A page that shows its working still has to run its own tool correctly.
• The gap this page fills: it does not out-compute the NOAA-method tools, and it says so. What it offers instead is a disclosed simplified model with every limit on the page, a worked example verified against the tool's own output rather than pasted from an almanac, half-hour and quarter-hour offsets the old tool lacked, and polar day and night handled as real answers instead of degenerate times. For planning a shoot, a hike or a school timetable, a known few-minute error beats an unknown one.

For solar-energy planning, day length alone is not the design figure: panel yield depends on sun angles and irradiance through the day, not just on how long the sun is up. Use this tool for the daylight window, then size the system with the cost per solar panel calculator. And if the same planning question involves moonlight or night skies, the sunrise and moonrise tab on the sun moon rising calculator covers the moon's side of the night.

Frequently asked questions

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