How to display date with human language like "Today at xx:xx pm", "Yesterday at xx:xx am"?

Question

I have a date "2014-07-02 20:57:38 +0000" and I want to format it as "Today at 8:57 pm". I want that if a string is yesterday, then display it as "Yesterday at 9:00 am". If it is neither today or yesterday, just show the actually date like "27/6 at 7:53 pm".

I was able to get the time with format like "8:57 AM" with the code below.

            var formatter : NSDateFormatter = NSDateFormatter()
            formatter.dateFormat = "h:mm a"

            // message.createdAt is the date
            let dateString = formatter.stringFromDate(message.createdAt)
            println(dateString)

            //output = 8:57 AM

However, when I use the following code, it returns a blank string.

            var formatter : NSDateFormatter = NSDateFormatter()
            formatter.dateFormat = "h:mm a"
            formatter.doesRelativeDateFormatting = true  //<-- This doesn't work

            let dateString = formatter.stringFromDate(message.createdAt)
            println(dateString)

            //output = (nothing, its a blank string)

How do I make this work and display "Today" or "Yesterday" in Swift?

Solution 1

The reason it's blank is that your date format only has time components. Combined with .doesRelativeDateFormatting that gives you the empty string. If you want that custom time format, I think you need separate formatters for the date and the time:

let now = NSDate()

let dateFormatter = NSDateFormatter()
dateFormatter.dateStyle = .MediumStyle
dateFormatter.doesRelativeDateFormatting = true

let timeFormatter = NSDateFormatter()
timeFormatter.dateFormat = "h:mm a"

let time = "\(dateFormatter.stringFromDate(now)), \(timeFormatter.stringFromDate(now))"
println(time)      // prints "Today, 5:10 PM"

Solution 2

With Swift 5.1, Apple Developer API Reference states about DateFormatter's dateFormat property:

You should only set this property when working with fixed format representations, as discussed in Working With Fixed Format Date Representations. For user-visible representations, you should use the dateStyle and timeStyle properties, or the setLocalizedDateFormatFromTemplate(_:) method if your desired format cannot be achieved using the predefined styles; both of these properties and this method provide a localized date representation appropriate for display to the user.

---

The following Playground sample code shows how to display your dates in the desired format using dateStyle, timeStyle and doesRelativeDateFormatting properties:

import Foundation

let now = Date() // 2019-08-09 12:25:12 +0000
let yesterday = Calendar.current.date(byAdding: .day, value: -1, to: now)! // 2019-08-08 12:25:12 +0000
let aWeekAgo = Calendar.current.date(byAdding: .weekOfMonth, value: -1, to: now)! // 2019-08-02 12:25:12 +0000

let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .long
dateFormatter.timeStyle = .short
dateFormatter.doesRelativeDateFormatting = true

let nowString = dateFormatter.string(from: now)
print(nowString) // prints: Today at 2:25 PM

let yesterdayString = dateFormatter.string(from: yesterday)
print(yesterdayString) // prints: Yesterday at 2:25 PM

let aWeekAgoString = dateFormatter.string(from: aWeekAgo)
print(aWeekAgoString) // prints: August 2, 2019 at 2:25 PM

Solution 3

Give this a try in Swift:

let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .short
dateFormatter.timeStyle = .short
dateFormatter.doesRelativeDateFormatting = true

let date = Date()
let dateString = dateFormatter.string(from:date)