first few obvious strokes.. 128 

function a($)
    dim $b
    $ = split($,'/')
    $b = 0,0,3,0,1,0,1,0,0,1,0,1,0
    $a = ''+$[0]+'/'+$[1]+'/'+ (31-$b[$[1]]+($[0] mod 4 = )*(2=$[1]))
endfunction


Edited by Jochen (2011-10-24 09:33 AM)
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