关于Date的一些常用的方法总结

最近在新的项目中用了很多关于时间计算的东西，各种需求也是让人难受的不行，其中也遇到不少关于时区的坑，特此前来总结一下关于date的常用延展方法，以后还会陆续补充

把当前时间转换成当前时区

func passDate() -> Date{
    let zone = NSTimeZone.system
    let time:Int = zone.secondsFromGMT(for: self)
    let nowDate = self.addingTimeInterval(TimeInterval(time))
    return nowDate
}

date转字符串

/// - Parameters:
///   - date: 某天
///   - string: 时间格式
/// - Returns: string
func getSomeDayToString(date:Date,string:String) -> String {
    let nowDate = date
    let timeZone = TimeZone.init(identifier: "UTC")
    let formatter = DateFormatter()
    formatter.timeZone = timeZone
    formatter.locale = Locale.init(identifier: "zh_CN")
    formatter.dateFormat = string
    return formatter.string(from: nowDate)
}

获取某天的指定时间

/// - Parameter time: 时间 （19：00）
/// - Returns: date
func getCurrentDaySomeTime(time:String,someday:Date) -> Date {
    let timeZone = TimeZone.init(identifier: "UTC")
    let formatter = DateFormatter()
    formatter.timeZone = timeZone
    formatter.locale = Locale.init(identifier: "zh_CN")
    formatter.dateFormat = "yyyy年MM月dd日"
    var today = formatter.string(from: someday)
    today = today + " " + time
    let newformatter = DateFormatter()
    newformatter.dateFormat = "yyyy年MM月dd日 HH:mm"
    newformatter.timeZone = timeZone
    newformatter.locale = Locale.init(identifier: "zh_CN")
    let newDate = newformatter.date(from: today)!
    return newDate
}

date转时间戳

func dateToTimestamp(date:Date) -> TimeInterval {
    let invale = date.timeIntervalSince1970
    return invale
}

获取周六晚上七点的时间

func getSatdayNight()->Date{
    
    let gmt = NSTimeZone(abbreviation: "GMT")
    let gregorian = NSCalendar(identifier: .gregorian)
    gregorian?.timeZone = gmt as! TimeZone
    var components = gregorian?.components([ .weekday,.day,.hour,.minute,.second], from: self)
    components?.setValue(6 - (components?.weekday)!, for: .weekday)
    components?.setValue(1, for: .day)
    components?.setValue(19 - (components?.hour)! - 1, for: .hour)
    components?.setValue(60 - (components?.minute)! - 1, for: .minute)
    components?.setValue(60 - (components?.second)!, for: .second)
    return (gregorian?.date(byAdding: components!, to: self, options: NSCalendar.Options(rawValue: 0))!)!
    
}

昨天

func getLastDay() ->Date {

    let calendar  = NSCalendar.init(identifier: .gregorian)
    var comps = calendar?.components(.day, from: self)
    comps?.setValue(-1, for: .day)
    
    return (calendar?.date(byAdding: comps!, to: self, options: NSCalendar.Options(rawValue: 0))!)!
    
}

前三天

func getLastThreeDay() ->Date {
    
    let calendar  = NSCalendar.init(identifier: .gregorian)
    var comps = calendar?.components(.day, from: self)
    comps?.setValue(-2, for: .day)
    
    return (calendar?.date(byAdding: comps!, to: self, options: NSCalendar.Options(rawValue: 0))!)!
    
}

今天稍后两小时

func getTodaylater() -> Date{
    let calendar  = NSCalendar.init(identifier: .gregorian)
    var comps = calendar?.components(.hour, from: self)
    comps?.setValue(2, for: .hour)

    return (calendar?.date(byAdding: comps!, to: self, options: NSCalendar.Options(rawValue: 0))!)!
}

比较当前时间和指定时间

/// - Parameter customDate: 要比较的时间
/// - Returns: 早于当前时间返回YES，否则NO
func compareTime(customDate:Date) -> Bool {
    let isTrue:ComparisonResult = self.passDate().compare(customDate)
    if isTrue == ComparisonResult.orderedAscending {
        return true
    }else{
        return false
    }
}