Get current date/time in seconds

Question

How do I get the current date/time in seconds in Javascript?

Answer 1

On some day in 2020, inside Chrome 80.0.3987.132, this gives 1584533105

~~(new Date()/1000) // 1584533105
Number.isInteger(~~(new Date()/1000)) // true

Answer 2

These JavaScript solutions give you the milliseconds or the seconds since the midnight, January 1st, 1970.

The IE 9+ solution(IE 8 or the older version doesn't support this.):

var timestampInMilliseconds = Date.now();
var timestampInSeconds = Date.now() / 1000; // A float value; not an integer.
    timestampInSeconds = Math.floor(Date.now() / 1000); // Floor it to get the seconds.
    timestampInSeconds = Date.now() / 1000 | 0; // Also you can do floor it like this.
    timestampInSeconds = Math.round(Date.now() / 1000); // Round it to get the seconds.

To get more information about Date.now(): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/now

The generic solution:

// ‘+’ operator makes the operand numeric.
// And ‘new’ operator can be used without the arguments ‘(……)’.
var timestampInMilliseconds = +new Date;
var timestampInSeconds = +new Date / 1000; // A float value; not an intger.
    timestampInSeconds = Math.floor(+new Date / 1000); // Floor it to get the seconds.
    timestampInSeconds = +new Date / 1000 | 0; // Also you can do floor it like this.
    timestampInSeconds = Math.round(+new Date / 1000); // Round it to get the seconds.

Be careful to use, if you don't want something like this case.

if(1000000 < Math.round(1000000.2)) // false.

Answer 3

 Date.now()

gives milliseconds since epoch. No need to use new.

Check out the reference here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/now

(Not supported in IE8.)

Answer 4

Based on your comment, I think you're looking for something like this:

var timeout = new Date().getTime() + 15*60*1000; //add 15 minutes;

Then in your check, you're checking:

if(new Date().getTime() > timeout) {
  alert("Session has expired");
}

Answer 5

// The Current Unix Timestamp
// 1443535752 seconds since Jan 01 1970. (UTC)

// Current time in seconds
console.log(Math.floor(new Date().valueOf() / 1000));  // 1443535752
console.log(Math.floor(Date.now() / 1000));            // 1443535752
console.log(Math.floor(new Date().getTime() / 1000));  // 1443535752

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

jQuery

console.log(Math.floor($.now() / 1000));               // 1443535752

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Answer 6

Using new Date().getTime() / 1000 is an incomplete solution for obtaining the seconds, because it produces timestamps with floating-point units.

const timestamp = new Date() / 1000; // 1405792936.933
// Technically, .933 would be milliseconds. 

A better solution would be:

// Rounds the value
const timestamp = Math.round(new Date() / 1000); // 1405792937

// - OR -

// Floors the value
const timestamp = new Date() / 1000 | 0; // 1405792936

Values without floats are also safer for conditional statements, as the float may produce unwanted results. The granularity you obtain with a float may be more than needed.

if (1405792936.993 < 1405792937) // true