Time and Date Manipulation

Working with times and dates can be tricky in programming languages. For this reason, most languages have some sort of built-in Date object that helps to make the process easier. JavaScript is no exception, and we’ll be taking a look at how that works.

The UNIX epoch

The UNIX epoch is an arbitrary date of January 1, 1970 which is used in programming as a reference point in time from which to measure dates. This allows dates to be expressed as an integer that represents the number of seconds since the epoch. As we can imagine, this produces some very large numbers, and there’s a potential problem looming in 2038 when the number of seconds since the epoch will be greater than $2,147,483,647$, which is the maximum value that some programming languages can deal with. Fortunately, JavaScript will be fine, as it can handle bigger values than this.

Times and dates

Date objects contain information about dates and times. Each object represents a single moment in time.

In JavaScript, we can use a constructor function to create a new Date object using the new operator. Try entering the following code: