javascript difference between two dates in days begining year code example

Example 1: js get difference in days

const date1 = new Date('19/1/2021');
const date2 = new Date('20/1/2021');
const diffTime = Math.abs(date2 - date1);
const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24)); 
console.log(diffTime + " milliseconds");
console.log(diffDays + " days");

Example 2: calculate days between two dates in javascript

<input id="first" value="25/2/2021"/>
<input id="second" value="26/2/2021"/>