Nur Rony
Polyglot Programmer, DevOps and Forever Learner

Extract Unix timestamp in Javascript

Extract Unix timestamp in Javascript

We frequently need to calculate with unix timestamp. There are several ways to grab the timestamp. For current unix timestamp easiest and fastest way is

const dateTime = Date.now();  
const timestamp = Math.floor(dateTime / 1000);  

or

const dateTime = new Date().getTime();  
const timestamp = Math.floor(dateTime / 1000);  

To get unix timestamp of a specific date pass YYYY-MM-DD or YYYY-MM-DDT00:00:00Z as parameter of Date constructor. For example

const dateTime = new Date('2012-06-08').getTime();  
const timestamp = Math.floor(dateTime / 1000);

You can just add a + (unary plus) sign also when declaring a Date object like below

const dateTime = +new Date();  
const timestamp = Math.floor(dateTime / 1000);  

or for specific date

const dateTime = +new Date('2012-06-08');  
const timestamp = Math.floor(dateTime / 1000);

Under the hood the runtime calls valueOf method of the Date object. Then the unary + operator calls toNumber() with that returned value. For detailed explanation please check the following links