get difference of dates in days 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: moment js difference between two dates

var admission = moment('{date1}', 'DD-MM-YYYY'); 
var discharge = moment('{date2}', 'DD-MM-YYYY');
discharge.diff(admission, 'days');