(sunrise/sunset) ( timestamp latitude longitude quot -- new-timestamp )


Vocabulary
calendar.private

Inputs
timestampan object
latitudean object
longitudean object
quotan object


Outputs
new-timestampan object


Definition
USING: calendar kernel math math.functions ;

IN: calendar.private

: (sunrise/sunset)
( timestamp latitude longitude quot -- new-timestamp )
[ [ [ hour-angle ] curry ] dip [ swap ] curry compose ] dip
[ 4 * ] compose compose [ [ [ noon ] ] ] dip
[ [ equation-of-time ] tri + round >integer minutes time- ]
curry compose preserve-gmt-offset ; inline