check date difference is greater is month in moment code example

Example 1: moment js check if date is greater than

let A = moment('2020-01-02');
let B = moment('2020-01-01');
let C = moment('2020-01-03');
console.log(A.diff(B, 'days'));// => 1
console.log(A.diff(C, 'days'));// => -1

Example 2: moment js get date 1 month

var currentDate = moment('2015-10-30');
var futureMonth = moment(currentDate).add(1, 'M');
var futureMonthEnd = moment(futureMonth).endOf('month');

if(currentDate.date() != futureMonth.date() && futureMonth.isSame(futureMonthEnd.format('YYYY-MM-DD'))) {
    futureMonth = futureMonth.add(1, 'd');
}

console.log(currentDate);
console.log(futureMonth);