JSFiddle - React, Tailwind, and code Playground
JavaScript
const registrationDate = '2001-01-01T00:00:00.000Z';
const regDate = registrationDate.split('.')[0]
const todaysDate = new Date().toISOString().split('.')[0];
const trialPeriod = todaysDate - regDate;
console.log(trialPeriod);