Creating Relative Date and Time Formatter in Swift (e.g: in 1 day ago, 5 minutes ago, in 2 hours go, etc)

Relative Date and Time example

In iOS 13.0 and above, we have access to a new date formatter class called RelativeDateTimeFormatter that allows us to format dates in a relative way. This means that we can display dates like “5 minutes ago,” “in 1 day,” “last week,” and so on.

To use this formatter class, we can create a custom Date extension that makes it easier to use. In the following example, we’ll create an extension that returns a relative time string based on the current date:

extension Date {
    func formatRelativeTime() -> String {
        let date = self

        let formatter = RelativeDateTimeFormatter()
        formatter.unitsStyle = .full
        let string = formatter.localizedString(for: date, relativeTo: Date())

        return string
    }
}

Here, we create a RelativeDateTimeFormatter object and set its units style to .full . This means that the formatter will use full names for units of time, such as “5 minutes ago” instead of “5 min ago.” We then use the formatter to get the relative time string for the given date.

Now, let’s see how we can use this extension to format dates:

import Foundation

// MARK: Extension
extension Date {
    func formatRelativeTime() -> String {
        let date = self

        let formatter = RelativeDateTimeFormatter()
        formatter.unitsStyle = .full
        let string = formatter.localizedString(for: date, relativeTo: Date())

        return string
    }
}

// MARK: Create a sample date
let string = "01/02/2016"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd/MM/yy"
let date = dateFormatter.date(from: string)

if let date = date {
    // MARK: Use the extension
    print(date.formatRelativeTime())
}

In this example, we first import the Foundation framework to use the Date class. We then create a sample date using the DateFormatter class, which takes a string and a format string to create a Date object. We then use the formatRelativeTime() method of our custom Date extension to get the relative time string for the date.

When we run this code, we get the output ”7 years ago”, which is the relative time string for the sample date we created.

The nice thing about this extension is that we can use it with any Date object. For example, we could use it to format the current date:

let now = Date()
print(now.formatRelativeTime()) // e.g: 5 minutes ago

Or we could use it to format a date that’s in the future:

let futureDate = Date().addingTimeInterval(60 * 60 * 24 * 7) // 1 week from now
print(futureDate.formatRelativeTime()) // e.g: in 6 days

In summary, using RelativeDateTimeFormatter and a custom Date extension makes formatting relative date and time strings in Swift simple and elegant.