How to Get a Timestamp in JavaScript

How do I get a timestamp in JavaScript?

Timestamp in milliseconds

To get the number of milliseconds since Unix epoch, call Date.now:

Date.now()

Alternatively, use the unary operator + to call Date.prototype.valueOf:

+ new Date()

Alternatively, call valueOf directly:

new Date().valueOf()

To support IE8 and earlier (see compatibility table), create a shim for Date.now:

if (!Date.now) {
    Date.now = function() { return new Date().getTime(); }
}

Alternatively, call getTime directly:

new Date().getTime()

Timestamp in seconds

To get the number of seconds since Unix epoch, i.e. Unix timestamp:

Math.floor(Date.now() / 1000)

Alternatively, using bitwise-or to floor is slightly faster, but also less readable and may break in the future (see explanations 1, 2):

Date.now() / 1000 | 0

Timestamp in milliseconds (higher resolution)

Use performance.now:

var isPerformanceSupported = (
    window.performance &&
    window.performance.now &&
    window.performance.timing &&
    window.performance.timing.navigationStart
);

var timeStampInMs = (
    isPerformanceSupported ?
    window.performance.now() +
    window.performance.timing.navigationStart :
    Date.now()
);

console.log(timeStampInMs, Date.now());

How do I get a UTC Timestamp in JavaScript?

Dates constructed that way use the local timezone, making the constructed date incorrect. To set the timezone of a certain date object is to construct it from a date string that includes the timezone. (I had problems getting that to work in an older Android browser.)
Note that getTime() returns milliseconds, not plain seconds.

For a UTC/Unix timestamp, the following should suffice:

Math.floor((new Date()).getTime() / 1000)

It will factor the current timezone offset into the result. For a string representation, David Ellis' answer works.

To clarify:

new Date(Y, M, D, h, m, s)

That input is treated as local time. If UTC time is passed in, the results will differ. Observe (I'm in GMT +02:00 right now, and it's 07:50):

> var d1 = new Date();
> d1.toUTCString();
"Sun, 18 Mar 2012 05:50:34 GMT" // two hours less than my local time
> Math.floor(d1.getTime()/ 1000)
1332049834 

> var d2 = new Date( d1.getUTCFullYear(), d1.getUTCMonth(), d1.getUTCDate(), d1.getUTCHours(), d1.getUTCMinutes(), d1.getUTCSeconds() );
> d2.toUTCString();
"Sun, 18 Mar 2012 03:50:34 GMT" // four hours less than my local time, and two hours less than the original time - because my GMT+2 input was interpreted as GMT+0!
> Math.floor(d2.getTime()/ 1000)
1332042634

Also note that getUTCDate() cannot be substituted for getUTCDay(). This is because getUTCDate() returns the day of the month; whereas, getUTCDay() returns the day of the week.

How to convert date to timestamp?

Split the string into its parts and provide them directly to the Date constructor:

Update:

var myDate = "26-02-2012";
myDate = myDate.split("-");
var newDate = new Date( myDate[2], myDate[1] - 1, myDate[0]);
console.log(newDate.getTime());

Convert a Unix timestamp to time in JavaScript

let unix_timestamp = 1549312452

// Create a new JavaScript Date object based on the timestamp

// multiplied by 1000 so that the argument is in milliseconds, not seconds.

var date = new Date(unix_timestamp * 1000);

// Hours part from the timestamp

var hours = date.getHours();

// Minutes part from the timestamp

var minutes = "0" + date.getMinutes();

// Seconds part from the timestamp

var seconds = "0" + date.getSeconds();

// Will display time in 10:30:23 format

var formattedTime = hours + ':' + minutes.substr(-2) + ':' + seconds.substr(-2);

console.log(formattedTime);

How to get timestamp value of only date

Create a date object, and set hours, minutes, seconds and milliseconds to zero

var date = new Date();

date.setHours(0,0,0,0);

var time = date.getTime();

console.log(time);

How to get the current date or/and time in seconds

var seconds = new Date().getTime() / 1000;

....will give you the seconds since midnight, 1 Jan 1970

Reference

Javascript get timestamp of 1 month ago

A simplistic answer is:

// Get a date object for the current time
var d = new Date();

// Set it to one month ago
d.setMonth(d.getMonth() - 1);

// Zero the time component
d.setHours(0, 0, 0, 0);

// Get the time value in milliseconds and convert to seconds
console.log(d/1000|0);

Note that if you subtract one month from 31 July you get 31 June, which will be converted to 1 July. similarly, 31 March will go to 31 February which will convert to 2 or 3 March depending on whether it's in a leap year or not.

So you need to check the month:

var d = new Date();
var m = d.getMonth();
d.setMonth(d.getMonth() - 1);

// If still in same month, set date to last day of 
// previous month
if (d.getMonth() == m) d.setDate(0);
d.setHours(0, 0, 0, 0);

// Get the time value in milliseconds and convert to seconds
console.log(d / 1000 | 0);

Note that JavaScript time values are in milliseconds since 1970-01-01T00:00:00Z, whereas UNIX time values are in seconds since the same epoch, hence the division by 1000.

How do you get the unix timestamp for the start of today in javascript?

var now = new Date();
var startOfDay = new Date(now.getFullYear(), now.getMonth(), now.getDate());
var timestamp = startOfDay / 1000;