Javascript 每5个月使用later.js的重复规则

我想每5个月制定一次计划。所以我试着这样做：

var startDate = new Date("2015-07-13T15:58:30.546Z");
var s = later.parse.recur().every(5).month();
s.on(startDate.getDate()).dayOfMonth();
var nextDates = later.schedule(s).next(3, startDate);
console.log(nextDates);

我希望得到这样的结果：

[ Fri Jul 13 2015 02:00:00 GMT+0200 (IST),
  Wed Dec 13 2016 02:00:00 GMT+0200 (IST),
  Mon May 13 2016 03:00:00 GMT+0300 (IDT) ]

[ Sun Nov 13 2015 02:00:00 GMT+0200 (IST),
  Fri Jan 13 2016 02:00:00 GMT+0200 (IST),
  Wed Jun 13 2016 03:00:00 GMT+0300 (IDT) ]

但是上面的代码产生了这个结果：

[ Fri Jul 13 2015 02:00:00 GMT+0200 (IST),
  Wed Dec 13 2016 02:00:00 GMT+0200 (IST),
  Mon May 13 2016 03:00:00 GMT+0300 (IDT) ]

[ Sun Nov 13 2015 02:00:00 GMT+0200 (IST),
  Fri Jan 13 2016 02:00:00 GMT+0200 (IST),
  Wed Jun 13 2016 03:00:00 GMT+0300 (IDT) ]

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我缺少什么？

可能是使用

启动

later.parse.recur()
 .every(5).month()
 .on(startDate.getDate()).dayOfMonth()
 .startingOn(startDate.getMonth() + 1)

已添加1，因为月份从0索引