Using dateFormatter's on swift - swift

var dateString = "Sat, 18 Jun 2016 11:00:00 +0900"
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "E, d MMM yyyy HH:mm:ss Z"
var dateFromString = dateFormatter.dateFromString(dateString)
dateFormatter.locale = NSLocale(localeIdentifier: "ko_KR")
dateFormatter.dateStyle = .FullStyle
var dateFromStringToKorean = dateFormatter.stringFromDate(dateFromString!)
This code working in Playground.
but When I build this code in my iPhone it doesn't work.
Could you tell me what's the problem of this code.


Set locale property of dateFormatter before using it, as below:
var dateString = "Sat, 18 Jun 2016 11:00:00 +0900"
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "E, d MMM yyyy HH:mm:ss Z"
dateFormatter.locale = NSLocale(localeIdentifier: "ko_KR")
dateFormatter.dateStyle = .FullStyle
var dateFromString = dateFormatter.dateFromString(dateString)
var dateFromStringToKorean = dateFormatter.stringFromDate(dateFromString!)

Related

How to format date as month and year in Swift? [duplicate]

How will I convert this datetime from the date?
From this: 2016-02-29 12:24:26
to: Feb 29, 2016
So far, this is my code and it returns a nil value:
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "MM-dd-yyyy"
dateFormatter.timeZone = NSTimeZone(name: "UTC")
let date: NSDate? = dateFormatter.dateFromString("2016-02-29 12:24:26")
print(date)

This may be useful for who want to use dateformatter.dateformat;
if you want 12.09.18 you use dateformatter.dateformat = "dd.MM.yy"
Wednesday, Sep 12, 2018 --> EEEE, MMM d, yyyy
09/12/2018 --> MM/dd/yyyy
09-12-2018 14:11 --> MM-dd-yyyy HH:mm
Sep 12, 2:11 PM --> MMM d, h:mm a
September 2018 --> MMMM yyyy
Sep 12, 2018 --> MMM d, yyyy
Wed, 12 Sep 2018 14:11:54 +0000 --> E, d MMM yyyy HH:mm:ss Z
2018-09-12T14:11:54+0000 --> yyyy-MM-dd'T'HH:mm:ssZ
12.09.18 --> dd.MM.yy
10:41:02.112 --> HH:mm:ss.SSS
Here are alternatives:
Era: G (AD), GGGG (Anno Domini)
Year: y (2018), yy (18), yyyy (2018)
Month: M, MM, MMM, MMMM, MMMMM
Day of month: d, dd
Day name of week: E, EEEE, EEEEE, EEEEEE

You have to declare 2 different NSDateFormatters, the first to convert the string to a NSDate and the second to print the date in your format.
Try this code:
let dateFormatterGet = NSDateFormatter()
dateFormatterGet.dateFormat = "yyyy-MM-dd HH:mm:ss"
let dateFormatterPrint = NSDateFormatter()
dateFormatterPrint.dateFormat = "MMM dd,yyyy"
let date: NSDate? = dateFormatterGet.dateFromString("2016-02-29 12:24:26")
print(dateFormatterPrint.stringFromDate(date!))
Swift 3 and higher:
From Swift 3 NSDate class has been changed to Date and NSDateFormatter to DateFormatter.
let dateFormatterGet = DateFormatter()
dateFormatterGet.dateFormat = "yyyy-MM-dd HH:mm:ss"
let dateFormatterPrint = DateFormatter()
dateFormatterPrint.dateFormat = "MMM dd,yyyy"
if let date = dateFormatterGet.date(from: "2016-02-29 12:24:26") {
print(dateFormatterPrint.string(from: date))
} else {
print("There was an error decoding the string")
}

Swift - 5.0
let date = Date()
let format = date.getFormattedDate(format: "yyyy-MM-dd HH:mm:ss") // Set output format
extension Date {
func getFormattedDate(format: String) -> String {
let dateformat = DateFormatter()
dateformat.dateFormat = format
return dateformat.string(from: self)
}
}
Swift - 4.0
2018-02-01T19:10:04+00:00 Convert Feb 01,2018
extension Date {
static func getFormattedDate(string: String , formatter:String) -> String{
let dateFormatterGet = DateFormatter()
dateFormatterGet.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
let dateFormatterPrint = DateFormatter()
dateFormatterPrint.dateFormat = "MMM dd,yyyy"
let date: Date? = dateFormatterGet.date(from: "2018-02-01T19:10:04+00:00")
print("Date",dateFormatterPrint.string(from: date!)) // Feb 01,2018
return dateFormatterPrint.string(from: date!);
}
}

Swift 3 and higher
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .medium
dateFormatter.timeStyle = .none
dateFormatter.locale = Locale.current
print(dateFormatter.string(from: date)) // Jan 2, 2001
This is also helpful when you want to localize your App. The Locale(identifier: ) uses the ISO 639-1 Code.
See also the Apple Documentation

Swift 3 version with the new Date object instead NSDate:
let dateFormatterGet = DateFormatter()
dateFormatterGet.dateFormat = "yyyy-MM-dd HH:mm:ss"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MMM dd,yyyy"
let date: Date? = dateFormatterGet.date(from: "2017-02-14 17:24:26")
print(dateFormatter.string(from: date!))
EDIT: after mitul-nakum suggestion

Convert #BatyrCan answer to Swift 5.3 with extra formats. Tested in Xcode 12.
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm:ss"
var dateFromStr = dateFormatter.date(from: "12:16:45")!
dateFormatter.dateFormat = "hh:mm:ss a 'on' MMMM dd, yyyy"
//Output: 12:16:45 PM on January 01, 2000
dateFormatter.dateFormat = "E, d MMM yyyy HH:mm:ss Z"
//Output: Sat, 1 Jan 2000 12:16:45 +0600
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
//Output: 2000-01-01T12:16:45+0600
dateFormatter.dateFormat = "EEEE, MMM d, yyyy"
//Output: Saturday, Jan 1, 2000
dateFormatter.dateFormat = "MM-dd-yyyy HH:mm"
//Output: 01-01-2000 12:16
dateFormatter.dateFormat = "MMM d, h:mm a"
//Output: Jan 1, 12:16 PM
dateFormatter.dateFormat = "HH:mm:ss.SSS"
//Output: 12:16:45.000
dateFormatter.dateFormat = "MMM d, yyyy"
//Output: Jan 1, 2000
dateFormatter.dateFormat = "MM/dd/yyyy"
//Output: 01/01/2000
dateFormatter.dateFormat = "hh:mm:ss a"
//Output: 12:16:45 PM
dateFormatter.dateFormat = "MMMM yyyy"
//Output: January 2000
dateFormatter.dateFormat = "dd.MM.yy"
//Output: 01.01.00
//Customisable AP/PM symbols
dateFormatter.amSymbol = "am"
dateFormatter.pmSymbol = "Pm"
dateFormatter.dateFormat = "a"
//Output: Pm
// Usage
var timeFromDate = dateFormatter.string(from: dateFromStr)
print(timeFromDate)

swift 3
let date : Date = Date()
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MMM dd, yyyy"
let todaysDate = dateFormatter.string(from: date)

I solved my problem to the format yyyy-MM-dd'T'HH:mm:ss.SSS'Z'(e.g 2018-06-15T00:00:00.000Z) with this:
func formatDate(date: String) -> String {
let dateFormatterGet = DateFormatter()
dateFormatterGet.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .medium
dateFormatter.timeStyle = .none
// dateFormatter.locale = Locale(identifier: "en_US") //uncomment if you don't want to get the system default format.
let dateObj: Date? = dateFormatterGet.date(from: date)
return dateFormatter.string(from: dateObj!)
}

iOS 15.0+
iPadOS 15.0+,
macOS 12.0+,
Mac Catalyst 15.0+,
tvOS 15.0+,
watchOS 8.0+,
Xcode 13.0+
Use formatted(date:time:)
let now = Date.now
let date = now.formatted(date: .abbreviated, time: .omitted)
Instead of .abbreviated, you may use another DateStyle such as .long, .numeric or define a custom format.
SwiftUI
Text(myDate, format: Date.FormatStyle(date: .numeric, time: .omitted))
or simply use:
Text(myDate, style: .date)
Reference
formatted(date:time:)
init(_:format:)
Text.DateStyle

Swift 4, 4.2 and 5
func getFormattedDate(date: Date, format: String) -> String {
let dateformat = DateFormatter()
dateformat.dateFormat = format
return dateformat.string(from: date)
}
let formatingDate = getFormattedDate(date: Date(), format: "dd-MMM-yyyy")
print(formatingDate)

Swift Version: 5.6 + Above
DateFormatter’s dateFormatter property is used to format Date with a custom String Pattern.
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MMM dd, yyyy"
let date = dateFormatter.string(from: datePicker.date)
print(date)
//Feb 28, 2022
If you want anything that shouldn’t be formatted and printed, then use single quotes around that word. Like; ‘at’
dateFormatter.dateFormat = "MMM dd, yyyy 'at' hh:MM a"
// May 29, 2022 at 12:05 PM
These are all possible Patterns to Format Date, Time & Time Zone.

Swift 3 with a Date extension
extension Date {
func string(with format: String) -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = format
return dateFormatter.string(from: self)
}
}
Then you can use it like so:
let date = Date()
date.string(with: "MMM dd, yyyy")

If you want to parse date from "1996-12-19T16:39:57-08:00", use the following format "yyyy-MM-dd'T'HH:mm:ssZZZZZ":
let RFC3339DateFormatter = DateFormatter()
RFC3339DateFormatter.locale = Locale(identifier: "en_US_POSIX")
RFC3339DateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
RFC3339DateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
/* 39 minutes and 57 seconds after the 16th hour of December 19th, 1996 with an offset of -08:00 from UTC (Pacific Standard Time) */
let string = "1996-12-19T16:39:57-08:00"
let date = RFC3339DateFormatter.date(from: string)
from Apple https://developer.apple.com/documentation/foundation/dateformatter

Another interessant possibility of format date. This screenshot belongs to Apple's App "News".
Here is the code:
let dateFormat1 = DateFormatter()
dateFormat1.dateFormat = "EEEE"
let stringDay = dateFormat1.string(from: Date())
let dateFormat2 = DateFormatter()
dateFormat2.dateFormat = "MMMM"
let stringMonth = dateFormat2.string(from: Date())
let dateFormat3 = DateFormatter()
dateFormat3.dateFormat = "dd"
let numDay = dateFormat3.string(from: Date())
let stringDate = String(format: "%#\n%# %#", stringDay.uppercased(), stringMonth.uppercased(), numDay)
Nothing to add to alternative proposed by lorenzoliveto. It's just perfect.
let dateFormat = DateFormatter()
dateFormat.dateFormat = "EEEE\nMMMM dd"
let stringDate = dateFormat.string(from: Date()).uppercased()

import UIKit
// Example iso date time
let isoDateArray = [
"2020-03-18T07:32:39.88Z",
"2020-03-18T07:32:39Z",
"2020-03-18T07:32:39.8Z",
"2020-03-18T07:32:39.88Z",
"2020-03-18T07:32:39.8834Z"
]
let dateFormatterGetWithMs = DateFormatter()
let dateFormatterGetNoMs = DateFormatter()
// Formater with and without millisecond
dateFormatterGetWithMs.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
dateFormatterGetNoMs.dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'"
let dateFormatterPrint = DateFormatter()
dateFormatterPrint.dateFormat = "MMM dd,yyyy"
for dateString in isoDateArray {
var date: Date? = dateFormatterGetWithMs.date(from: dateString)
if (date == nil){
date = dateFormatterGetNoMs.date(from: dateString)
}
print("===========>",date!)
}

just use below function to convert date format:-
let convertedFormat = convertToString(dateString: "2019-02-12 11:23:12", formatIn: "yyyy-MM-dd hh:mm:ss", formatOut: "MMM dd, yyyy") //calling function
print(convertedFormat) // feb 12 2019
func convertToString (dateString: String, formatIn : String, formatOut : String) -> String {
let dateFormater = DateFormatter()
dateFormater.timeZone = NSTimeZone(abbreviation: "UTC") as TimeZone!
dateFormater.dateFormat = formatIn
let date = dateFormater.date(from: dateString)
dateFormater.timeZone = NSTimeZone.system
dateFormater.dateFormat = formatOut
let timeStr = dateFormater.string(from: date!)
return timeStr
}

To convert 2016-02-29 12:24:26 into a date, use this date formatter:
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd hh:mm:ss"
Edit: To get the output Feb 29, 2016 use this date formatter:
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "MMM dd, yyyy"

For Swift 4.2, 5
Pass date and format as whatever way you want.
To choose format you can visit, NSDATEFORMATTER website:
static func dateFormatter(date: Date,dateFormat:String) -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = dateFormat
return dateFormatter.string(from: date)
}

Place it in extension and call it like below. It's easy to use throughout the application.
self.getFormattedDate(strDate: "20-March-2019", currentFomat: "dd-MMM-yyyy", expectedFromat: "yyyy-MM-dd")
Implementation
func getFormattedDate(strDate: String , currentFomat:String, expectedFromat: String) -> String{
let dateFormatterGet = DateFormatter()
dateFormatterGet.dateFormat = currentFomat
let date : Date = dateFormatterGet.date(from: strDate) ?? Date()
dateFormatterGet.dateFormat = expectedFromat
return dateFormatterGet.string(from: date)
}

From iOS 15 use something like this:
extension Date {
var string: String {
if #available(iOS 15.0, *) {
return self.formatted(date: .complete, time: .complete)
} else {
return self.description
}
}
}

Here is a full date format extension for swift
extension Date {
func getFormattedDate(format: String) -> String {
let dateformat = DateFormatter()
dateformat.dateFormat = format
return dateformat.string(from: self)
}
func getFormattedDate(style: DateFormatter.Style) -> String {
let dateformat = DateFormatter()
dateformat.dateStyle = style
return dateformat.string(from: self)
}
}
Usage
myDate.getFormattedDate(style: .medium) //medium, short, full, long
OR
myDate.getFormattedDate(format: "yyyy/MM/dd HH:mm:ss")

swift 3
func dataFormat(dataJ: Double) -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .long
dateFormatter.timeStyle = .none
let date = Date(timeIntervalSince1970: dataJ)
return (dataJ != nil) ? "Today, \(dateFormatter.string(from: date))" : "Date Invalid"
}

I recommend to add timezone by default. I will show an example for swift 5
1. new an extension file Date+Formatter.swift
import Foundation
extension Date {
func getFormattedDateString(format: String) -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = format
dateFormatter.timeZone = TimeZone.current
return dateFormatter.string(from: self)
}
}
Usage example
let date = Date()
let dateString = date.getFormattedDateString(format: "yyyy-MM-dd HH:mm:ss")
print("dateString > \(dateString)")
// print
// dateString > 2020-04-30 15:15:21

class Utils {
class func dateFormatter(_ date: Date, _ format: String) -> String {
let dateformat = DateFormatter()
dateformat.dateFormat = format
return dateformat.string(from: date)
}
}
print(Utils.dateFormatter(Date(), "EEEE, MMM d, yyyy"))
Create class name Utils import same function and you can use globally accesss any where with your date and formate

Date Formatter unexpected output

let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "MMMM dd, yyyy 'at' HH:mm:ss aa z"
dateFormatter.amSymbol = "AM"
let dateString = "February 02, 2022 at 10:49:06 AM GMT+3"
print(dateFormatter.date(from: dateString)!)
Prints -> 2022-02-01 21:49:06 +0000
why this prints 21:49 instead of 10:49?

So, yes, we're both missing something. The time format should be use hh not HH (HH is for 24 hour time and some weird conversation was going in there)
So, I tested in a Playground with...
let threeHoursFromGMT = Measurement(value: 3, unit: UnitDuration.hours).converted(to: UnitDuration.seconds).value
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "MMMM dd, yyyy 'at' hh:mm:ss aa z"
dateFormatter.amSymbol = "AM"
dateFormatter.timeZone = TimeZone.init(secondsFromGMT: Int(threeHoursFromGMT))
let dateString = "February 02, 2022 at 10:49:06 AM GMT+3"
let date = dateFormatter.date(from: dateString)!
dateFormatter.string(from: dateFormatter.date(from: dateString)!)
And it generated
"Feb 2, 2022 at 6:49 PM" // let date = dateFormatter.date(from: dateString)!
"February 02, 2022 at 10:49:06 AM GMT+3" // dateFormatter.string(from: dateFormatter.date(from: dateString)!)
The first output is based on my timezone (+11) and the second is based on the formatter requirements (using +3)

NSDateFormatter doesn't work on actual equipment [duplicate]

This question already has answers here:
What is the best way to deal with the NSDateFormatter locale "feature"?
(4 answers)
Closed 7 years ago.
I tried to use NSDateFormatter like following.
On simulator, it works fine. -> 2015-06-01
But, on actual equipment, it does't work. it'll be nil.
let d = "Wed Jul 01 04:48:51 +0000 2015"
let formatter = NSDateFormatter()
formatter.dateFormat = "EEE MMM dd HH:mm:ss Z yyyy"
if let date = formatter.dateFromString(d) {
formatter.dateFormat = "yyyy-MM-dd"
self.dateLabel?.text = formatter.stringFromDate(date)
}
Is this iPhone's problem?

Could be an issue with locale and 12/24-hour time handling.
Try forcing formatter's locale to be consistent for the date you are receiving.
let d = "Wed Jul 01 04:48:51 +0000 2015"
let formatter = NSDateFormatter()
formatter.dateFormat = "EEE MMM dd HH:mm:ss Z yyyy"
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
if let date = formatter.dateFromString(d) {
formatter.locale = NSLocale.currentLocale()
formatter.dateFormat = "yyyy-MM-dd"
self.dateLabel?.text = formatter.stringFromDate(date)
}
Check these question/answers for more info.

Show AM/PM in capitals in swift

I wrote the following code to show a datetime in a particular format:
let formatter = NSDateFormatter()
formatter.dateStyle = NSDateFormatterStyle.LongStyle
formatter.timeStyle = .MediumStyle
formatter.dateFormat = "HH:mm a 'on' MMMM dd, yyyy"
let dateString = formatter.stringFromDate(newDate!)
println(dateString)
Output
12:16 pm on July 17, 2015
I want to show 'pm' as 'PM'(in capitals) and if phone has 24 hours format then AM/PM should not appear. Please help me.

You can set your DateFormatter amSymbol and pmSymbol as follow:
Xcode 8.3 • Swift 3.1
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "h:mm a 'on' MMMM dd, yyyy"
formatter.amSymbol = "AM"
formatter.pmSymbol = "PM"
let dateString = formatter.string(from: Date())
print(dateString) // "4:44 PM on June 23, 2016\n"

Added some formats in one place. Hope someone get help.
Xcode 12 - Swift 5.3
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm:ss"
var dateFromStr = dateFormatter.date(from: "12:16:45")!
dateFormatter.dateFormat = "hh:mm:ss a 'on' MMMM dd, yyyy"
//Output: 12:16:45 PM on January 01, 2000
dateFormatter.dateFormat = "E, d MMM yyyy HH:mm:ss Z"
//Output: Sat, 1 Jan 2000 12:16:45 +0600
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
//Output: 2000-01-01T12:16:45+0600
dateFormatter.dateFormat = "EEEE, MMM d, yyyy"
//Output: Saturday, Jan 1, 2000
dateFormatter.dateFormat = "MM-dd-yyyy HH:mm"
//Output: 01-01-2000 12:16
dateFormatter.dateFormat = "MMM d, h:mm a"
//Output: Jan 1, 12:16 PM
dateFormatter.dateFormat = "HH:mm:ss.SSS"
//Output: 12:16:45.000
dateFormatter.dateFormat = "MMM d, yyyy"
//Output: Jan 1, 2000
dateFormatter.dateFormat = "MM/dd/yyyy"
//Output: 01/01/2000
dateFormatter.dateFormat = "hh:mm:ss a"
//Output: 12:16:45 PM
dateFormatter.dateFormat = "MMMM yyyy"
//Output: January 2000
dateFormatter.dateFormat = "dd.MM.yy"
//Output: 01.01.00
//Output: Customisable AP/PM symbols
dateFormatter.amSymbol = "am"
dateFormatter.pmSymbol = "Pm"
dateFormatter.dateFormat = "a"
//Output: Pm
// Usage
var timeFromDate = dateFormatter.string(from: dateFromStr)
print(timeFromDate)

Get NSDate and convert it from the 24 hour format to 12 hour format in swift

I've seen this post for other languages but not for swift. I have a date saved in the format of 2015-08-31 21:36:00 +0000 and I'm able to extract the day, month, year and weekday with the code below to produce Monday, August 31, 2015. When I try to use:
let hourInt = components.hour
var hourString = String(hourInt)
It prints a four hour difference. In this case "17" for the "21". How do I
display it as 9:36 P.M.?
let flags: NSCalendarUnit = NSCalendarUnit.CalendarUnitMinute | NSCalendarUnit.CalendarUnitHour | NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitWeekday | NSCalendarUnit.CalendarUnitMonth | NSCalendarUnit.CalendarUnitYear
let date = NSDate()
let dateFormatter: NSDateFormatter = NSDateFormatter()
let components = NSCalendar.currentCalendar().components(flags, fromDate: array.date)
let weekday = components.weekday
let weekdays = dateFormatter.weekdaySymbols
let weekdayString = weekdays[weekday-1] as! String
let month = components.month
let months = dateFormatter.monthSymbols
let monthString = months[month-1] as! String
let dayInt = components.day
var dayString = String(dayInt)
let year = components.year
let yearString = String(year)
println(weekdayString + ", " + monthString + " " + dayString + ", " + yearString)

Your date string suffix +0000 means it is UTC time if you want to display time at UTC you need to specify it when setting your date formatter.
let dateString = "2015-08-31 21:36:00 +0000"
let df = NSDateFormatter()
df.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
if let date = df.dateFromString(dateString) {
// now you have your date object
// to display UTC time you have to specify timeZOne UTC
df.timeZone = NSTimeZone(forSecondsFromGMT: 0)
df.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
let stringFromDate = df.stringFromDate(date)
println(stringFromDate) // "Monday, August 31, 2015 9:36:00 PM"
}

If you want to strip the time zone information, pass the GMT time zone.
This code does quite the same as yours
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "EEEE, MMMM dd, yyyy"
dateFormatter.timeZone = NSTimeZone(abbreviation: "GMT")
println(dateFormatter.stringFromDate(array.date))

Setting locale of NSDateFormatter to en_US_POSIX fixed issue for me.
let sharedFormatter:NSDateFormatter = {
let formatter = NSDateFormatter()
formatter.locale = NSLocale(localeIdentifier:"en_US_POSIX")
return formatter
}()
sharedFormatter.dateFormat = "MMM d YYYY, h:mm a"
let dateString = sharedFormatter.stringFromDate(NSDate())
// Aug 2 2016, 5:45 PM

Swift 5.0
let dateString = "2015-08-31 21:36:00 +0000"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
if let date = dateFormatter.date(from: dateString) {
// now you have your date object
// to display UTC time you have to specify timeZOne UTC
dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
dateFormatter.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
let stringFromDate = dateFormatter.string(from: date)
print(stringFromDate) // "Monday, August 31, 2015 9:36:00 PM"
}