It's only a rewite of jalaali-js in typescript. all credits goes to jalaali's contributor.
import { Jalaali } from "ts-jalaali";
const jalaali = Jalaali.toJalaali(1981, 8, 17);
const Jalaali = require('ts-jalaali').Jalaali;
const jalaali = Jalaali.toJalaali(1981, 8, 17);