Epoch time, also known as UNIX time, is the number of seconds that have elapsed since the Unix epoch, which was 00:00:00 UTC on 1 January 1970. It is used to represent date and time as a numerical value and is commonly used in many different programming languages. This article will explain in detail what epoch time is and how to get epoch time in Javascript.
What is Epoch Time?
Epoch time is a numerical way to store and calculate time that is independent of any time zone or location. It eliminates the problems created by different time zones being used in different places around the world. It is also useful for working with longer periods of time, since it counts in seconds and milliseconds instead of days, weeks, years, or months.
Epoch time allows developers to track the age of something in seconds, a feature that is especially useful when creating digital products like programs and games. It helps to ensure consistency because no matter where the code is used, the same epoch value will produce the same result.
Epoch time is also useful for tracking events that occur over a long period of time. For example, it can be used to track the time since a user last logged into a website or the time since a certain event occurred. This makes it easier to keep track of user activity and other important events.
How to Get Epoch Time in Javascript
In Javascript, you can get the current Epoch time in milliseconds by using the Date object. This object has many useful methods that can be used to get the current Unix timestamp, as well as create and manipulate dates.
The Date object includes a now() method that returns the current Epoch time in milliseconds. For example, you could use it like this:
let now = Date.now();
This would return the current epoch timestamp in milliseconds. You can use this code snippet to get the current Unix timestamp in any Javascript program.
In addition to the now() method, the Date object also includes a getTime() method which returns the same result. This method can be used to get the current Unix timestamp in any Javascript program as well.
Understanding the Current Epoch Time with Javascript
Once you have the current epoch time, you can use it to understand the date and time that it represents. Fortunately, the Date object offers an array of methods for manipulating Epoch time values. For example, you can use the .getUTCSeconds() method to get the seconds value for a given Epoch timestamp:
let date = new Date(now);
let seconds = date.getUTCSeconds();
This code snippet will return the number of seconds associated with that particular Unix timestamp. This can be useful for extracting specific information from epoch values, such as days, weeks, or months.
In addition to the .getUTCSeconds() method, you can also use the .getUTCMinutes() and .getUTCHours() methods to get the minutes and hours associated with a given Epoch timestamp. This can be useful for creating more detailed calculations and understanding the exact time associated with a given Unix timestamp.
Working with the Date Object in Javascript
The Date object allows you to manipulate dates and times by creating a Date instance and then calling various methods on it. For instance, you can use the setUTCSeconds() method to set a number of seconds for a given epoch timestamp:
let date = new Date(now);
date.setUTCSeconds(60);
This code snippet sets a Unix timestamp at 60 seconds from 1 January 1970. You can pass any number of seconds into this method to manipulate a given Unix timestamp.
In addition to the setUTCSeconds() method, the Date object also provides other methods for manipulating dates and times. For example, the getUTCMonth() method can be used to retrieve the month of a given date, while the getUTCDate() method can be used to retrieve the day of the month. By combining these methods, you can easily create a date object that represents a specific date and time.
Using Epoch Time with Date Libraries in Javascript
In addition to manipulating epoch values directly with the Date object, developers can use functionality provided by specialized libraries. These libraries provide methods to work with dates and times, formatted as strings or dates. Many libraries offer methods to convert epoch timestamps into other formats, such as ISO 8601 or RFC 3339.
For example, Moment.js is a popular date library for Javascript which allows you to format and present time values in an easier and more intuitive way. It offers a method to convert epoch values into readable strings:
let dateString = moment(now).format(“DD/MM/YYYY HH:mm:ss”);
This code snippet will convert a given Unix timestamp into a string formatted as DD/MM/YYYY HH:mm:ss. This is just one example of how specialized libraries can be used for working with dates and times in Javascript.
In addition to Moment.js, there are other libraries available for working with dates and times in Javascript. For example, Luxon is a library that provides a more modern approach to date and time manipulation. It offers a range of features, such as time zone support, formatting, and parsing. Luxon also provides methods for converting epoch timestamps into other formats.
Benefits of Using Epoch Time in Javascript
Epoch time offers several benefits over traditional date formats and can simplify the way dates and times are managed in your code. One important benefit is that epoch time is not influenced by any specific time zone or location. This makes it ideal for applications that are used around the world. Additionally, it eliminates any potential confusion caused by different date formats being used in different countries.
Epoch time also allows developers to manipulate dates more easily, since it simply requires adding or subtracting the corresponding number of seconds. This is especially useful when dealing with longer periods of time, such as weeks or months.
Other Uses of Epoch Time in Javascript
In addition to working with dates and times, epoch time can also be used for other purposes. For example, it can be used as a reference point for measuring performance in programs and games. Developers can use epoch timestamps to calculate how long certain operations took, get an accurate measure of user interaction times, or determine the number of frames per second in video games.
Examples of Code Used to Get Epoch Time in Javascript
The following examples illustrate the different ways you can use code snippets to get epoch time in Javascript:
- Use the Date Object’s now() method:
let now = Date.now(); - Get UTC seconds from a given epoch timestamp:
let date = new Date(now);
let seconds = date.getUTCSeconds(); - Set UTC seconds for a given epoch timestamp:
let date = new Date(now);
date.setUTCSeconds(60); - Get a readable string from an epoch timestamp using Moment.js:
let dateString = moment(now).format(“DD/MM/YYYY HH:mm:ss”);
// Epoch timestamp of the upcoming event
const eventTimestamp = 1679433600; // This represents a future date and time
// Get the current epoch timestamp
const currentTimestamp = Date.now() / 1000; // Convert milliseconds to seconds
// Calculate the time remaining in seconds
const timeRemaining = eventTimestamp - currentTimestamp;
// Convert time remaining into hours, minutes, and seconds
const hours = Math.floor(timeRemaining / 3600);
const minutes = Math.floor((timeRemaining % 3600) / 60);
const seconds = Math.floor(timeRemaining % 60);
// Display the time remaining
console.log(`Time remaining: ${hours} hours, ${minutes} minutes, ${seconds} seconds`);
Troubleshooting Tips for Working with Epoch Time and Javascript
When dealing with epoch timestamps in Javascript, it’s important to ensure that your code is robust enough to handle boundary cases and errors gracefully. For example, be mindful of leap seconds when manipulating longer periods of time. Additionally, make sure you are using UTC-based methods instead of local ones when dealing with dates.
It’s also important to test your code thoroughly when working with dates and times. Since these values vary depending on where the code is used, you should make sure that all possible cases are covered before deployment.
by the Bito team. 
