See how many hours of daylight a place gets on any date, how much daylight was gained or lost since yesterday, and how day length changes through the year compared with other latitudes. Everything is calculated in your browser.
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Daylight–
Sunrise–
Sunset–
Night–
Usable light (civil)–
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Solar noon–
Day length through the year
Move over the chart to read the day length on any date.
Month by month
This date at other latitudes
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How to use the Day Length Calculator
Choose a city, press Use my location, or type a latitude and longitude (north and east positive).
Pick a date. Today is selected automatically; use the day buttons to step forward or back.
Press Calculate day length to see daylight hours, the change since yesterday and this week, and sunrise and sunset times.
Read the year chart: your location is the thick green line; tick Compare latitudes to see how day length changes nearer the equator or the pole.
Use the tables for month by month numbers or other latitudes, and download the whole year as a CSV file.
Why day length changes through the year
Earth's axis is tilted by about 23.44° relative to its orbit. As Earth goes around the Sun, the tilt makes the Sun appear further north (up to +23.44° declination in June) or further south (down to −23.44° in December). When the Sun is on your side of the equator it follows a longer, higher arc across your sky, so the day is longer than 12 hours; when it is on the other side the arc is shorter. At the equator the arc is always cut roughly in half by the horizon, so day length stays close to 12 hours all year.
The formula used is the standard sunrise equation: cos H = (sin h − sin φ · sin δ) / (cos φ · cos δ), where φ is latitude, δ is the Sun's declination and h = −0.833° is the altitude of the Sun's centre at sunrise and sunset. The day length is 2H ÷ 15 hours (H in degrees). If the right-hand side is less than −1 the Sun never sets; if it is greater than 1 it never rises.
Daylight at different latitudes
Approximate hours of daylight on the solstices and equinox in the Northern Hemisphere (swap June and December for the Southern Hemisphere):
Latitude
Example place
December solstice
March equinox
June solstice
0°
Quito, Singapore (1°N)
12h 07m
12h 07m
12h 07m
20°N
Mexico City, Mumbai
10h 55m
12h 07m
13h 21m
30°N
New Orleans, Cairo
10h 13m
12h 07m
14h 05m
40°N
New York, Madrid
9h 20m
12h 08m
15h 01m
50°N
Prague, Winnipeg
8h 04m
12h 10m
16h 22m
60°N
Oslo, Anchorage (61°N)
5h 52m
12h 13m
18h 52m
70°N
Northern Norway
0h (polar night)
12h 18m
24h (midnight sun)
Values are rounded and vary by a minute or two from year to year. Use the calculator for exact figures on a specific date.
Tips
Gardeners use day length to time planting: many plants flower in response to day length (photoperiod), not temperature.
If you feel low in winter, compare your city with places further south on the chart to see how much daylight you are missing.
For photography planning, combine this with sunrise and sunset times and the golden hour.
The earliest sunset and the latest sunrise do not fall on the shortest day; they are shifted by a couple of weeks because of the equation of time.
Frequently asked questions
How is day length calculated?
Day length is the time between sunrise and sunset, when the top edge of the sun is on the horizon (its centre 0.833° below it, allowing for atmospheric refraction). The calculator finds the sun's declination for each date with the NOAA solar equations and solves cos H = (sin(−0.833°) − sin φ sin δ) / (cos φ cos δ) for the hour angle H; the day length is then 2H at 4 minutes per degree.
Why is the day longer than 12 hours at the equinox?
At the March and September equinoxes the sun's centre spends about 12 hours above the horizon, but sunrise and sunset are measured at the top edge of the sun, and refraction lifts the image of the sun slightly. Together these add several minutes, so most places see 12 hours and 6 to 10 minutes of daylight on the equinox.
When do days get longer fastest?
Day length changes fastest around the equinoxes in March and September and slowest near the solstices in June and December. The rate also grows with latitude: near 40° the change peaks at around 2 to 3 minutes a day, while above 60° it can exceed 5 minutes a day.
Which day has the most daylight?
In the Northern Hemisphere the longest day is the June solstice (June 20 or 21) and the shortest is the December solstice (December 21 or 22). In the Southern Hemisphere it is the other way round. The calculator finds the exact longest and shortest day for the chosen year and place.
What does usable light (civil) mean?
Civil daylight runs from civil dawn to civil dusk, when the sun is less than 6° below the horizon. During civil twilight there is usually enough light for outdoor activities without artificial lighting, so it is a practical measure of usable light, about 30 to 60 minutes longer than sunrise to sunset.
Does longitude or time zone change day length?
Hardly. Day length depends almost entirely on latitude and date. Longitude and the time zone shift the clock times of sunrise and sunset, but not how long the sun is up, apart from tiny differences because the sun's declination changes slightly during the day.
What happens above the Arctic Circle?
North of about 66.6° the sun stays up all day around the June solstice (midnight sun) and does not rise around the December solstice (polar night). The calculator then shows 24 hours or 0 hours of daylight, and the year chart flattens at the top or bottom.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.