Sunrise/Sunset Approximation

Estimate day length using latitude and day-of-year approximation.

Scratchpad (not saved)

deg

What This Calculator Does

Estimate day length using latitude and day-of-year approximation.

It combines Latitude, Day of Year to estimate Daylight Duration, Approx Sunrise, Approx Sunset.

Formula & Method

Core equations: Approximate daylight from latitude/day-of-year via declination \delta and hour angle H_0=\arccos(-\tan\phi\tan\delta); day length =\frac{2H_0}{15} hours.

Notation used in the formulas: R = Daylight Duration; x_{1} = Latitude; x_{2} = Day of Year.

Method summary: inputs are normalized to consistent units, core equations are evaluated, then secondary values are derived and rounded for display.

Use this calculator for quick scenario analysis. Start with baseline values, change one driver at a time, and compare how sensitive the results are to each input shown above.

Inputs Used

  • Latitude: Used directly in the calculation.
  • Day of Year: Used directly in the calculation.

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