Daylight length shifts with the seasons — fastest around the equinoxes and flattest near the solstices. Pick a city to see today’s daylight and the change through the year.
It is sunset minus sunrise, using the standard definition of the sun’s centre crossing -0.833° (including atmospheric refraction).
Daylight length follows a sine curve: the slope is steepest near the equinoxes (fastest change) and near zero around the solstices (almost no change).
Roughly, yes — but the earliest sunrise and latest sunset don’t fall exactly on the solstice due to the equation of time. This tool scans the whole year for the actual longest and shortest daylight.
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