var f = function(i){return new Date(2014,i,0).getDate();};
JSON.stringify([1,2,3,4,5,6,7,8,9,10,11,12].map(f)) == JSON.stringify([31,28,31,30,31,30,31,31,30,31,30,31]);
:P
var f = function(i){return new Date(2014,i,0).getDate();};
JSON.stringify([1,2,3,4,5,6,7,8,9,10,11,12].map(f)) == JSON.stringify([31,28,31,30,31,30,31,31,30,31,30,31]);
:P