Calendar widget dates generator using ES6

CalendarWidgetGenerator

function *calendar (month, year) {

  var c = new Date(year, month, 0).getDate();
  var l = new Date(year, month - 1, 0).getDate();
  var o = new Date(year, month - 1, 1).getDay();

  var p = o > 0 ? 1 - o : -6;
  var m = 42 + p;

  while (p < m)
    yield p < 0 ? ++p + l : p < c ? ++p : ++p % c;

}

for (var i of calendar(3, 2015)) 
  console.log(i);