如何獲取當月的開始日期和結束日期（Swift 3）

Question

我正在嘗試以dd/MM/yyyy格式獲取當月的開始和結束日期。 我嘗試使用在這個SO Question 中回答的擴展名。但它似乎不是我想要的（格式不同，而且它給了我上個月的最后日期和當前月份的最后一個日期）。 有人能幫我嗎。

擴展類：

extension Date {
    func startOfMonth() -> Date? {
        let comp: DateComponents = Calendar.current.dateComponents([.year, .month, .hour], from: Calendar.current.startOfDay(for: self))
        return Calendar.current.date(from: comp)!
    }

    func endOfMonth() -> Date? {
        var comp: DateComponents = Calendar.current.dateComponents([.month, .day, .hour], from: Calendar.current.startOfDay(for: self))
        comp.month = 1
        comp.day = -1
        return Calendar.current.date(byAdding: comp, to: self.startOfMonth()!)
    }
}

我的結構：

struct Constants{

    // keys required for making a Login call (POST Method)
    struct LoginKeys {
       .....
    }

    struct RankingKeys {

        static let DateFrom = String(describing: Date().startOfMonth()) //giving me 2016-11-30 16:00:00 +0000 
        static let DateTo  = String(describing: Date().endOfMonth())
//2016-12-30 16:00:00 +0000
    }
}

預期結果：

DateFrom  = "01/12/2016"
DateTo = "31/12/2016"

Answer 1

你應該寫這個簡單的代碼：

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

開始日期：

let comp: DateComponents = Calendar.current.dateComponents([.year, .month], from: date)
let startOfMonth = Calendar.current.date(from: comp)!
print(dateFormatter.string(from: startOfMonth))

結束日期：

var comps2 = DateComponents()
comps2.month = 1
comps2.day = -1
let endOfMonth = Calendar.current.date(byAdding: comps2, to: startOfMonth)
print(dateFormatter.string(from: endOfMonth!)) 

Answer 2

這就是我正在使用的。 很簡單，但它的工作原理。

extension Calendar {

func dayOfWeek(_ date: Date) -> Int {
    var dayOfWeek = self.component(.weekday, from: date) + 1 - self.firstWeekday

    if dayOfWeek <= 0 {
        dayOfWeek += 7
    }

    return dayOfWeek
}

func startOfWeek(_ date: Date) -> Date {
    return self.date(byAdding: DateComponents(day: -self.dayOfWeek(date) + 1), to: date)!
}

func endOfWeek(_ date: Date) -> Date {
    return self.date(byAdding: DateComponents(day: 6), to: self.startOfWeek(date))!
}

func startOfMonth(_ date: Date) -> Date {
    return self.date(from: self.dateComponents([.year, .month], from: date))!
}

func endOfMonth(_ date: Date) -> Date {
    return self.date(byAdding: DateComponents(month: 1, day: -1), to: self.startOfMonth(date))!
}

func startOfQuarter(_ date: Date) -> Date {
    let quarter = (self.component(.month, from: date) - 1) / 3 + 1
    return self.date(from: DateComponents(year: self.component(.year, from: date), month: (quarter - 1) * 3 + 1))!
}

func endOfQuarter(_ date: Date) -> Date {
    return self.date(byAdding: DateComponents(month: 3, day: -1), to: self.startOfQuarter(date))!
}

func startOfYear(_ date: Date) -> Date {
    return self.date(from: self.dateComponents([.year], from: date))!
}

func endOfYear(_ date: Date) -> Date {
    return self.date(from: DateComponents(year: self.component(.year, from: date), month: 12, day: 31))!
}
}

如何使用

let calendar: Calendar = Calendar.current
let startDate = calendar.startOfMonth(Date())
print("startDate :: \(startDate)")

Answer 3

這是為 Date 創建擴展的簡單解決方案，如下所示：

extension Date {

func startOfMonth() -> Date {
    let interval = Calendar.current.dateInterval(of: .month, for: self)
    return (interval?.start.toLocalTime())! // Without toLocalTime it give last months last date
}

func endOfMonth() -> Date {
    let interval = Calendar.current.dateInterval(of: .month, for: self)
    return interval!.end
}

// Convert UTC (or GMT) to local time
func toLocalTime() -> Date {
    let timezone    = TimeZone.current
    let seconds     = TimeInterval(timezone.secondsFromGMT(for: self))
    return Date(timeInterval: seconds, since: self)
}}

然后像這樣調用你的 Date 實例

print(Date().startOfMonth())
print(Date().endOfMonth())

Answer 4

使用 Swift 3 和 iOS 10，我發現最簡單的方法是Calendar的dateInterval(of:for:) ：

guard let interval = calendar.dateInterval(of: .month, for: Date()) else { return }

然后使用日期格式化程序打印日期：

let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-yyyy"
let dateText = formatter.string(from: interval.start)

Answer 5

此擴展程序根據您的需要為您提供預期的輸出

這里我返回日期

extension NSDate {
    func startOfMonth() -> NSDate? {
        guard
            let cal: NSCalendar = NSCalendar.currentCalendar(),
            let comp: NSDateComponents = cal.components([.Year, .Month], fromDate: self) else { return nil }
        comp.to12pm()
        let dateformattor = NSDateFormatter()
        dateformattor.dateFormat = "yyyy-MM-dd"
        dateformattor.timeZone = NSTimeZone.localTimeZone()
        let dt2 = dateformattor.stringFromDate(cal.dateFromComponents(comp)!)
        print(dt2)

        dateformattor.dateFormat = "yyyy-MM-dd"
        dateformattor.timeZone = NSTimeZone.init(abbreviation: "UTC")

        return dateformattor.dateFromString(dt2)
    }

    func endOfMonth() -> NSDate? {
        guard
            let cal: NSCalendar = NSCalendar.currentCalendar(),
            let comp: NSDateComponents = NSDateComponents() else { return nil }
        comp.month = 1
        comp.day = -1
        comp.to12pm()
        let dateformattor = NSDateFormatter()
        dateformattor.dateFormat = "yyyy-MM-dd"
        dateformattor.timeZone = NSTimeZone.localTimeZone()
        let dt2 = dateformattor.stringFromDate(cal.dateByAddingComponents(comp, toDate: self.startOfMonth()!, options: [])!)

        dateformattor.dateFormat = "yyyy-MM-dd"
        dateformattor.timeZone = NSTimeZone.init(abbreviation: "UTC")

        return dateformattor.dateFromString(dt2)
    }
}
internal extension NSDateComponents {
    func to12pm() {
        self.hour = 12
        self.minute = 0
        self.second = 0
    }
}

**輸出 ：- **

Start Date of Month :- 2016-12-01 00:00:00 +0000
End Date of Month :- 2016-12-31 00:00:00 +0000

Answer 6

為了完整起見，API dateInterval(of:start:interval:for:)的Calendar受讓人的電流的開始日期和時間間隔（以秒計） month到inout參數。

日期格式化程序考慮當前時區。

let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "dd/MM/yyyy"

var startDate = Date()
var interval = TimeInterval()
Calendar.current.dateInterval(of: .month, start: &startDate, interval: &interval, for: Date())
let endDate = Calendar.current.date(byAdding: .second, value: Int(interval) - 1, to: startDate)!

let fromDate = formatter.string(from: startDate)
let toDate = formatter.string(from: endDate)
print(fromDate, toDate)