week-of-year ( timestamp day -- n )

Vocabulary

formatting.private

Inputs

timestamp	an object
day	an object

Outputs

n

an object

Definition

USING: calendar calendar.private kernel math ;

IN: formatting.private

: week-of-year ( timestamp day -- n )
    [ dup clone first-day-of-year dup clone ] [ day-this-week ]
    bi* swap [ time- duration>days ] curry bi@ dup 0 <
    [ 7 + - ] [ drop ] if 7 + 7 /i ;