Getting started with Moment.apex
Date/Time Manipulation
You can choose from a wide range of APIs provided by Moment.apex to manipulate Date/Time.
new Moment().add(1, 'month').subtract(3, 'days'); // 2018-06-01 11:25:37
new Moment().year(2018).month(3).day(1).hour(12).minute(0).second(0); // 2018-03-01 12:00:00
new Moment().year(); // 2018