Javascript get current time in milliseconds

Get the current time in milliseconds using JavaScript

In this tutorial, we are going to learn about how to get the current time in milliseconds using JavaScript.

In JavaScript, we can get the current by calling a getTime() on the new Date() constructor.

const currentTime = new Date().getTime();

To get the current time in milliseconds, divide the current time with 1000 , because 1second = 1000 milliseconds.

const currentTime = new Date().getTime(); const milliseconds = currentTime/1000; console.log(milliseconds);

The / operator in the above code returns the result of dividing the first operand by the second.

Similarly, we can also use the Date.now() method to get the current time in Milliseconds.

const milliseconds = Date.now(); console.log(milliseconds);

The Date.now() method returns the current time in milliseconds since the epoch (January 1, 1970).

Источник

Date.prototype.getTime()

The getTime() method of Date instances returns the number of milliseconds for this date since the epoch, which is defined as the midnight at the beginning of January 1, 1970, UTC.

Try it

Syntax

Return value

A number representing the timestamp, in milliseconds, of this date. Returns NaN if the date is invalid.

Description

Date objects are fundamentally represented by a timestamp, and this method allows you to retrieve the timestamp. You can use this method to help assign a date and time to another Date object. This method is functionally equivalent to the valueOf() method.

Reduced time precision

To offer protection against timing attacks and fingerprinting, the precision of new Date().getTime() might get rounded depending on browser settings. In Firefox, the privacy.reduceTimerPrecision preference is enabled by default and defaults to 2ms. You can also enable privacy.resistFingerprinting , in which case the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds , whichever is larger.

// reduced time precision (2ms) in Firefox 60 new Date().getTime(); // 1519211809934 // 1519211810362 // 1519211811670 // … // reduced time precision with `privacy.resistFingerprinting` enabled new Date().getTime(); // 1519129853500 // 1519129858900 // 1519129864400 // … 

Examples

Using getTime() for copying dates

Constructing a date object with the identical time value.

// Since month is zero based, birthday will be January 10, 1995 const birthday = new Date(1994, 12, 10); const copy = new Date(); copy.setTime(birthday.getTime()); 

Measuring execution time

Subtracting two subsequent getTime() calls on newly generated Date objects, give the time span between these two calls. This can be used to calculate the executing time of some operations. See also Date.now() to prevent instantiating unnecessary Date objects.

let end, start; start = new Date(); for (let i = 0; i  1000; i++)  Math.sqrt(i); > end = new Date(); console.log(`Operation took $end.getTime() - start.getTime()> msec`); 

Note: In browsers that support the Web Performance API’s high-resolution time feature, Performance.now() can provide more reliable and precise measurements of elapsed time than Date.now() .

Specifications

Browser compatibility

BCD tables only load in the browser

See also

Found a content problem with this page?

This page was last modified on Jun 1, 2023 by MDN contributors.

Your blueprint for a better internet.

MDN

Support

Our communities

Developers

Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.
Portions of this content are ©1998– 2023 by individual mozilla.org contributors. Content available under a Creative Commons license.

Источник

Date.now()

The Date.now() static method returns the number of milliseconds elapsed since the epoch, which is defined as the midnight at the beginning of January 1, 1970, UTC.

Try it

Syntax

Return value

A number representing the timestamp, in milliseconds, of the current time.

Description

Reduced time precision

To offer protection against timing attacks and fingerprinting, the precision of Date.now() might get rounded depending on browser settings. In Firefox, the privacy.reduceTimerPrecision preference is enabled by default and defaults to 2ms. You can also enable privacy.resistFingerprinting , in which case the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds , whichever is larger.

// reduced time precision (2ms) in Firefox 60 Date.now(); // 1519211809934 // 1519211810362 // 1519211811670 // … // reduced time precision with `privacy.resistFingerprinting` enabled Date.now(); // 1519129853500 // 1519129858900 // 1519129864400 // … 

Examples

Measuring time elapsed

You can use Date.now() to get the current time in milliseconds, then subtract a previous time to find out how much time elapsed between the two calls.

const start = Date.now(); doSomeLongRunningProcess(); console.log(`Time elapsed: $Date.now() - start> ms`); 

For more complex scenarios, you may want to use the performance API instead.

Specifications

Browser compatibility

BCD tables only load in the browser

See also

Found a content problem with this page?

This page was last modified on Jun 1, 2023 by MDN contributors.

Your blueprint for a better internet.

MDN

Support

Our communities

Developers

Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.
Portions of this content are ©1998– 2023 by individual mozilla.org contributors. Content available under a Creative Commons license.

Источник

Date.prototype.getMilliseconds()

The getMilliseconds() method of Date instances returns the milliseconds for this date according to local time.

Try it

Syntax

Return value

An integer, between 0 and 999, representing the milliseconds for the given date according to local time. Returns NaN if the date is invalid.

Examples

Using getMilliseconds()

The milliseconds variable has value 0 , based on the value of the Date object xmas95 , which doesn’t specify the milliseconds component, so it defaults to 0.

const xmas95 = new Date("1995-12-25T23:15:30"); const milliseconds = xmas95.getMilliseconds(); console.log(milliseconds); // 0 

Specifications

Browser compatibility

BCD tables only load in the browser

See also

Found a content problem with this page?

This page was last modified on Jun 1, 2023 by MDN contributors.

Your blueprint for a better internet.

MDN

Support

Our communities

Developers

Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.
Portions of this content are ©1998– 2023 by individual mozilla.org contributors. Content available under a Creative Commons license.

Источник