%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/jd2dow {
    1 add 7 mod 
} bind def

/test.end {
    ( ) print
    test.count 0 gt {
        (Passed ) print
        test.pass (...) cvs print
        (/) print
        test.count (...) cvs print
        ( \() print
        test.pass 100 mul test.count idiv (...) cvs print
        (%\)) print
        (\r\n) print
    } if
} bind def

/ymd2jd {
    4 dict begin
    aload pop
    /d exch def
    /m exch def
    /y exch def
    /mn m 14 sub 12 idiv def
    y 4800 add mn add 1461 mul 4 idiv
    mn 12 mul neg 2 sub m add 367 mul 12 idiv add
    y 4900 add mn add 100 idiv 3 mul 4 idiv sub
    d add
    32075 sub
    end
} bind def

/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} bind def

/jd2ymd {
    15 dict begin
    /y 4716 def
    /v 3 def
    /j 1401 def
    /u 5 def
    /m 2 def
    /s 153 def
    /n 12 def
    /w 2 def
    /r 4 def
    /B 274277 def
    /p 1461 def
    /C -38 def
    dup
    4 mul B add 146097 idiv 3 mul 4 idiv C add j add add /f exch def
    r f mul v add /e exch def
    e p mod r idiv u mul w add /h exch def
    /day h s mod u idiv 1 add def
    /month h s idiv m add n mod 1 add def
    /year e p idiv y sub n m add month sub n idiv add def
    [ year month day ]
    end
} bind def

/test {
    /test.count test.count 1 add def
    {
        /test.pass test.pass 1 add def
    } {
        ( ) print
        test.count (....) cvs print
        (-fail) print
    } ifelse
} bind def


% end included library code

/seizetheday {
    0 dict begin
    /dayofweek exch def
    /weekcount exch def
    /month exch def
    /year exch def
    /dt [ year month 1 ] ymd2jd def
    /wd dt jd2dow def
    wd 0 eq {
        /wd 7 def
    } if
    wd dayofweek ne {
        /dt dayofweek 7 add wd sub 7 mod dt add def
    } if
    weekcount 1 gt {
        /dt dt weekcount 1 sub 7 mul add def
    } if
    dt jd2ymd aload pop
    exch
    month ne {
        pop 0
    } if
    exch
    year ne {
        pop 0
    } if
    end
} bind def

(seizetheday) test.start
2024 4 3 2 seizetheday 16 eq test
2025 10 2 4 seizetheday 9 eq test
2026 8 5 3 seizetheday 0 eq test
test.end