Day Length Rate of Change
How fast the days are getting longer or shorter · minutes per day ·
NOAA solar formula
cos H = (sin(−0.833°) − sin φ sin δ) / (cos φ cos δ)
day length = 2H / 15° h
change = today − yesterday
φ latitude, δ sun’s declination
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Today
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Location
Day length
vs yesterday
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