2020-01-22 -> 2019-12-22 -> 2019-11-22
varx=newDate();date.setMonth(x.getMonth()-1)date// 2020-01-22T08:55:29.971Zdate.setMonth(x.getMonth()-1)date// 2019-12-22T08:55:29.971Zdate.setMonth(x.getMonth()-1)date// 2019-11-22T08:55:29.971Z
Original by Github issue
https://github.com/YumaInaura/YumaInaura/issues/3002