iOS Swift. How to work with DateFormatter

How to display date in specific format. For example, 01 August 1989,  or in specific locale (Russian: 1 августа 1989) or in specific timezone(MSK or PST)

let date = Date()
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd MMM yyyy HH:mm"
label1.text = "With Format: \(dateFormatter.string(from: date))"
        
let locale = Locale(identifier: "ru")
dateFormatter.locale = locale
label2.text = "With RU Locale:  \(dateFormatter.string(from: date))"
        
let timeZone = TimeZone(abbreviation: "MSK")
dateFormatter.timeZone = timeZone
label3.text = "With MSK TimeZone: \(dateFormatter.string(from: date))"

Result

What if we get string with data in specific format and we need to display it in other format(and in specific timezone and specific locale). 

For example, 

input format: yyyy-MM-dd'T'HH:mm:ss.SSSZ

output format: dd MMMM yyyy HH:mm

Firstly, we set input format to DateFormatter and convert input string to date. After that we set nre format and convert date to new string.

 let dateStr = "2016-10-31T14:51:21.780+08:00"
 label4.text = "Before: \(dateStr)"
 let dateFormatter = DateFormatter()
 dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
        
 let timeZone = TimeZone(abbreviation: "MSK")
 dateFormatter.timeZone = timeZone
        
 let locale = Locale(identifier: "ru")
 dateFormatter.locale = locale
        
 let date = dateFormatter.date(from: dateStr)
        
 dateFormatter.dateFormat = "dd MMMM yyyy HH:mm"
 let formattedDateStr = dateFormatter.string(from: date!)
        
 label5.text = "After: \(formattedDateStr)"

Conversion Result