solar-noon ( timestamp longitude -- new-timestamp )
Calendar

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Vocabulary
calendar

Inputs

timestamp	a timestamp
longitude	a real

Outputs

new-timestamp

a timestamp

Word description
Calculates solar noon of the given day at the given longitude in the given timezone.

Definition

USING: accessors calendar.private kernel math math.functions ;

IN: calendar

: solar-noon ( timestamp longitude -- new-timestamp )
    [ [ noon ] ] dip [ 4 * ] curry compose [
        [ equation-of-time ] bi + minutes time-
        [ round >integer ] change-second
    ] curry preserve-gmt-offset ;