swift日期操作

简介：本文将介绍一些关于swift中对于日期的格式化与获取，支持swift4.0

 extension Date {

     //格式化日期
     func getDateString() -> String{
         let  dateFormater = DateFormatter.init()
         //EEEE:星期几
         //YYYY:年份
         //MM:月份
         //dd:几号
         //HH:小时
         //mm:分钟
         //ss:秒
         //zzz:时区号

         dateFormater.dateFormat = "EEEE-YYYY-MM-dd HH:mm:ss:zzz"
         let dateStr = dateFormater.string(from: self)

         return dateStr
     }

     //获取某个日期为星期几
     func getDateWeekday() ->String{
         let weekdaysTitleArr = ["周日","周一","周二","周三","周四","周五","周六"]
         let timeInterval:TimeInterval = self.timeIntervalSince1970
         let days = Int(timeInterval/)
         let weekday = ((days + )%+)%
         return weekdaysTitleArr[weekday]
     }

     //将日期转换为时间戳(10位)
     func getTimeStamp() -> Int{
         let timeInterval:TimeInterval = self.timeIntervalSince1970
         let timeStamp = Int(timeInterval)
         return timeStamp
     }
 }

 class Utility: NSObject {

     //根据时间戳获取时间字符串
     class func getDateStringFromTimestamp(_ timestamp:Int64) ->String{
         let timeInterval:TimeInterval = TimeInterval(timestamp)
         let date = Date(timeIntervalSince1970: timeInterval)
         return date.getDateString()
     }

     //根据时间戳获取日期对象
     class func getDateFromTimestamp(_ timestamp:Int64) ->Date{
         let timeInterval:TimeInterval = TimeInterval(timestamp)
         let date = Date(timeIntervalSince1970: timeInterval)
         return date
     }

     //获取两个日期的间隔天数
     class func getDateInterval(dateA:Date,dateB:Date) ->Int{
         let interval = dateA.timeIntervalSince(dateB)
         let days = Int(interval/(**))
 //        let hours = Int(interval/(60*60))
 //        let mins = Int(interval/60)
         return days
     }
 }

最后就是方法的调用与后台的输出

         let date = Date()
         print(date.getDateString())
         print(date.getDateWeekday())
         print(date.getTimeStamp())

         let dateA = Utility.getDateFromTimestamp()
         let dateB = Utility.getDateFromTimestamp()
         let days = Utility.getDateInterval(dateA: dateA, dateB: dateB)
         print(days)    

PS:   http://tool.chinaz.com/Tools/unixtime.aspx   这个网址可以在线转换时间戳