days-in-month.js 250 Bytes Raw Blame History Permalink 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 "use strict"; var getMonth = Date.prototype.getMonth; module.exports = function () { switch (getMonth.call(this)) { case 1: return this.getFullYear() % 4 ? 28 : 29; case 3: case 5: case 8: case 10: return 30; default: return 31; } };