Swift 3.0 - 4.2

import Foundation

extension String {

    func toDate(withFormat format: String = "yyyy-MM-dd HH:mm:ss")-> Date?{

        let dateFormatter = DateFormatter()
        dateFormatter.timeZone = TimeZone(identifier: "Asia/Tehran")
        dateFormatter.locale = Locale(identifier: "fa-IR")
        dateFormatter.calendar = Calendar(identifier: .gregorian)
        dateFormatter.dateFormat = format
        let date = dateFormatter.date(from: self)

        return date

    }
}

extension Date {

    func toString(withFormat format: String = "EEEE ، d MMMM yyyy") -> String {

        let dateFormatter = DateFormatter()
        dateFormatter.locale = Locale(identifier: "fa-IR")
        dateFormatter.timeZone = TimeZone(identifier: "Asia/Tehran")
        dateFormatter.calendar = Calendar(identifier: .persian)
        dateFormatter.dateFormat = format
        let str = dateFormatter.string(from: self)

        return str
    }
}

在swift4,

    var Msg_Date_ = "2019-03-30T05:30:00+0000"

    let dateFormatterGet = DateFormatter()
    dateFormatterGet.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
    let dateFormatterPrint = DateFormatter()
    dateFormatterPrint.dateFormat = "MMM dd yyyy h:mm a"  //"MMM d, h:mm a" for  Sep 12, 2:11 PM
    let datee = dateFormatterGet.date(from: Msg_Date_)
    Msg_Date_ =  dateFormatterPrint.string(from: datee ?? Date())

    print(Msg_Date_)

//输出:- 2019年3月30日05:30 PM

从iOS 15.0开始，我们可以更快速地将字符串转换为日期:

let strategy = Date.ParseStrategy(format: "\(year: .defaultDigits)-\(month: .twoDigits)-\(day: .twoDigits)T\(hour: .twoDigits(clock: .twentyFourHour, hourCycle: .zeroBased)):\(minute: .twoDigits):\(second: .twoDigits)\(timeZone: .iso8601(.short))", timeZone: .current)
let date = try? Date("2016-04-14T10:44:00+0000", strategy: strategy)

斯威夫特5.6

这是一个简单的方法来获得一个字符串，并将其转换回字符串与日期的结构通过字符串扩展

日期字符串示例"2022-03-15T07:13:49.607+00:00"

如果日期的格式不是“yyyy-MM-dd'T hh:mm:ss”。SSSSSSSZ” 它将返回01-01-70

import Foundation

extension String {

  func convertToDate() -> String {
   
      let dateFormatter = DateFormatter()
      dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSSSSSZ"
      if let dt = dateFormatter.date(from: self) {
          dateFormatter.dateFormat = "MM-dd-yy"
          let formatedStringDate = dateFormatter.string(from: dt)
              return formatedStringDate
      }
    
   
      return "01-01-70"
  }
}

试试下面的日期格式。

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZZZ"
let date = dateFormatter. dateFromString (strDate)

希望能有所帮助。

Swift 4.1:

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZZZ"
let date = dateFormatter.date(from: strDate)

斯威夫特5。看是否一个日期已经通过:

let expiryDate = "2020-01-10" // Jan 10 2020

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"

if Date() < dateFormatter.date(from: expiryDate) ?? Date() {
    print("Not Yet expiryDate")
} else {
    print("expiryDate has passed")
}