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

Vocabulary

calendar.private

Inputs

timestamp	an object
latitude	an object
longitude	an object
quot	an object

Outputs

new-timestamp

an object

Definition

USING: calendar kernel math math.functions ;

IN: calendar.private

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