Javascript - Previous month computation from a current date

javascript

Solution

Simple subject the month by 1 would get a valid date -- never would `setMonth` method return an invalid `Date` object (the same as `setDate`, `setYear` and the `Date` constructor):

var date = new Date(2012, 02, 31); // 2012-03-31
date.setMonth(date.getMonth() - 1); // This gets 2012-03-02

I don't quite clear what date you expected, the last day of the previous month or just the day one month earlier?

Problem

I have a below JS where I get the max date that is user allowed to enter from a backend script: ``` var max_date = new Date(pdate + " " + ptime); ``` where pdate and ptime is fetched from a script. Now I need to set the min date as 1 month less than max_date ``` if (max_date.getMonth() == 0) subtractyear = 1; var min_date = new Date(Date.UTC(max_date.getFullYear() - subtractyear,max_date.getMonth() - 1,max_date.getDate(),max_date.getHours(),0,0)); ``` My issue is that if max_date is March 31 - then will the min_date be rolled over to Feb 28 or Feb 29 or Feb 31 or Feb 30? If the date formed is an incorrect date - say Feb 30 how can I rectify this?

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