from Date I just want to subtract 1 day in javascript/angularjs

问题

with the help of new Date() how i can achieve this. my code :

var temp =new Date("October 13, 2014 22:34:17");
console.log(new Date(temp-1));

requirement:

before: Aug 4, 2014 11:59pm (EDT)
after:   Aug 3, 2014 11:59pm (EDT)

回答1:

You need to specify what amount of time you are subtracting. At the moment its 1, but 1 what? Therefore, try getting the days using getDate() and then subtract from that and then set the date with setDate().

E.g.

var temp = new Date("October 13, 2014 22:34:17");
temp.setDate(temp.getDate()-1);

回答2:

The simple answer is that you want to subtract a days worth of milliseconds from it. So something like the following

var today = new Date('October 13, 2014 22:34:17');
var yesterday = new Date(today.getTime() - (24*60*60*1000));
console.log(yesterday);

The problem with this is that this really gives you 24 hours earlier, which isn't always a day earlier due to things such as changes in Daylight Saving Time. If this is what you want, fine. If you want something more sophisticated, check out moment.js

回答3:

You can simply subtract one day from today date like this:

var yesterday = new Date(new Date().setDate(new Date().getDate()-1));

来源：https://stackoverflow.com/questions/25136760/from-date-i-just-want-to-subtract-1-day-in-javascript-angularjs