get difference between two dates javascript moment code example

Example 1: moment check days of difference between days

var a = moment([2007, 0, 29]);
var b = moment([2007, 0, 28]);
a.diff(b, 'days')

Example 2: vue moment js difference between dates in minutes

var now  = "04/09/2013 15:00:00";
var then = "04/09/2013 14:20:30";

moment.utc(moment(now,"DD/MM/YYYY HH:mm:ss").diff(moment(then,"DD/MM/YYYY HH:mm:ss"))).format("HH:mm:ss")

// outputs: "00:39:30"