So siehts ganz gut aus !

node_modules/es5-ext/date/#/days-in-month.js

@@ -0,0 +1,17 @@
+"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;
+	}
+};