JSFiddle - React, Tailwind, and code Playground
by Hans PUFAL
JavaScript
function sundaysInMonth (m, y) {
var days = new Date ( y, m, 0).getDate ();
days -= new Date ([m,days,y].join ('/')).getDay ();
return days / 7;
}
for (var r = [], i = 12; i--;)
r.unshift (sundaysInMotnth (i, 2012));
alert( '2012 : ' + r.join (', '));