• 将ISO8601字符串转换为日期

        let isoDate = "2016-04-14T10:44:00+0000"

    let dateFormatter = DateFormatter()
    dateFormatter.locale = Locale(identifier: "en_US_POSIX") // set locale to reliable US_POSIX
    dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
    let date = dateFormatter.date(from:isoDate)!

• 从日期获取年，月，日和小时的日期部分

  let calendar = Calendar.current
  

  let components = calendar.dateComponents([.year, .month, .day, .hour], from: date)

• 最后创建一个新Date对象并删除分钟和几秒钟

  let finalDate = calendar.date(from:components)
  

还请考虑ISO8601DateFormatteriOS 10 / macOS 12中引入的便捷格式化程序：

    let isoDate = "2016-04-14T10:44:00+0000"

    let dateFormatter = ISO8601DateFormatter()
    let date = dateFormatter.date(from:isoDate)!