Persian Date
A lightweight but professional library for working with Persian dates.
This supports Persian (Jalali) and gregorian calendar and from v2.0 supports Nodejs.
Open the devtools and in the Console tab use the PersianDate.
npm i @alireza-ab/persian-date
let date = new PersianDate([1400,1,1],'jalali');
date.toString();
1400/01/01
date.diff('1399/9','date') + ' days';
120 days
date.addDay(5).toString();
1400/01/06
date.isAfter('1399/12/30');
true