equation-of-time ( timestamp -- minutes )


Vocabulary
calendar.private

Inputs
timestampan object


Outputs
minutesan object


Definition
USING: math math.functions ;

IN: calendar.private

:: equation-of-time ( timestamp -- minutes )
timestamp fractional-year :> γ 0.000075 0.001868 γ cos * +
0.032077 γ sin * - 0.014615 γ 2 * cos * - 0.040849 γ 2 *
sin * - 229.18 * ;