How to get Epoch/UNIX timestamps in javascript

Unix/Epoch Time now:

In JavaScript, getting Epoch timestamps is straightforward, and there are multiple methods to accomplish this task. This article explores different ways to get Epoch timestamps in JavaScript and provides practical use cases.

Using the `Date.now()` Method

JavaScript provides the Date.now() method to fetch the current time in milliseconds since the Unix Epoch. You can use this method to calculate the current Epoch timestamp.


    let epochTime = Date.now() / 1000;
    document.write("Current Epoch timestamp: " + epochTime);

This code snippet utilizes the Date.now() method to obtain the current time in milliseconds and then converts it to seconds to obtain the Epoch timestamp.

Use Case 1: Logging timestamps


    let epochTime = Date.now() / 1000;
    let data = "Sensor data reading...";
    document.write(data + " - timestamp: " + epochTime);

In this example, JavaScript code is adapted for logging data with timestamps. It first obtains the current Epoch timestamp and then combines it with sensor data for logging.

Use Case 2: Time Duration Calculation


    let startTime = Date.now() / 1000;

    // Perform a task or operation

    let endTime = Date.now() / 1000;
    let timeElapsed = endTime - startTime;

    document.write("Time taken: " + timeElapsed + " seconds");

This use case demonstrates how to measure the time taken for a task. It records the start and end times in Date.now() and calculates the time elapsed in seconds.

Using the `Math.floor()` Function

You can also fetch the current Epoch timestamp in the Date object and the getTime() method, and then apply Math.floor() to round it down to the nearest second.


    let currentTime = new Date().getTime();
    let epochTime = Math.floor(currentTime / 1000);
    document.write("Current Epoch timestamp: " + epochTime);

This code snippet showcases how to obtain the current Epoch timestamp in the Date object and round it down to the nearest second.

Use Case 3: Expiry timestamp for Cache


    let currentTime = new Date().getTime();
    let epochTime = Math.floor(currentTime / 1000);

    let cacheKey = "cached_data";
    let expiryTime = epochTime + 600; // 10 minutes from now

    document.write("Cached data that expires at " + expiryTime);

    if (epochTime > expiryTime) {
        document.write("Cache expired. Recaching data...");
        // Re-cache the data
    }

In this example, JavaScript code calculates the expiry time for cache data and checks if the cache has expired.

Use Case 4: Event Scheduling


    let currentTime = new Date().getTime();
    let epochTime = Math.floor(currentTime / 1000);
    let eventTime = epochTime + 3600; // 1 hour from now

    let checkEvent = setInterval(function() {
        currentTime = new Date().getTime();
        epochTime = Math.floor(currentTime / 1000);

        if (epochTime >= eventTime) {
            clearInterval(checkEvent);
            document.write("Event occurred!");
        }
    }, 60000); // Check every minute

This use case demonstrates how to schedule an event to occur in the future. JavaScript code adds 3600 seconds (1 hour) to the current time to set the event time and continuously checks for its occurrence.

These code examples illustrate how to get Epoch/UNIX timestamps in JavaScript and showcase their applications in practical scenarios. Whether you need to log data with timestamps, calculate time durations, set cache expiry times, or schedule events, Epoch timestamps are versatile tools in JavaScript for precise time-related operations.