How to use this tool
- Choose your place and a date. The first place is the one all differences are measured against.
- Add places to compare. You can compare up to four places. Each place has its own colour in the table and the chart; search for a city or remove a place at any time.
- Read the table. For the selected date it lists sunrise, sunset and day length in each place’s own local time, the difference in day length compared with your first place, and how high the sun climbs at noon.
- Read the chart. One line per place shows the hours of daylight for every day of the year. Where lines cross, the two places have the same day length.
Why daylight differs between cities
The main reason is latitude. Because Earth’s axis is tilted by about 23.4°, the further a place is from the equator, the bigger the swing between summer and winter: close to the equator days stay near 12 hours all year, at 60° N they range from about 6 to more than 18 hours, and beyond the polar circles there are days without sunset or sunrise. The guide why days are longer in summer explains the geometry.
Hemisphere flips the seasons: when Oslo has its longest day in June, Sydney has its shortest.
Clock times add a second layer. Two cities with the same day length can still see sunrise at quite different clock times, because of where they lie within their time zone and whether they use daylight saving time. That is why the table always shows local times.
Last updated September 24, 2026