How Can I Get Timestamps in JavaScript?

Retrieving Timestamps in JavaScript

Timestamping plays a crucial role in web development for tasks such as tracking events, managing state, and ensuring data integrity. In JavaScript, there are several methods to obtain a timestamp, representing the current date and time as a numerical value.

Timestamp in milliseconds

To retrieve the number of milliseconds since the Unix epoch (00:00:00 UTC on January 1, 1970), use the Date.now() method:

Date.now()

Alternatively, you can use the unary operator to call Date.prototype.valueOf or call valueOf directly:

+ new Date()
new Date().valueOf()

Timestamp in seconds (Unix timestamp)

To obtain the Unix timestamp, which represents the number of seconds since the Unix epoch, use the following formula:

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

Timestamp in milliseconds (higher resolution)

For higher precision, considering fractional milliseconds, the following approach using performance.now may be employed:

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

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

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