Swift 3 - 查找两个日期之间的日历天数

Question

我在 Swift 2.3 中的做法是：

let currentDate         = NSDate()
let currentCalendar     = NSCalendar.currentCalendar()

var startDate : NSDate?
var endDate   : NSDate?

// The following two lines set the `startDate` and `endDate` to the start of the day

currentCalendar.rangeOfUnit(.Day, startDate: &startDate, interval: nil, forDate: currentDate)
currentCalendar.rangeOfUnit(.Day, startDate: &endDate, interval: nil, forDate: self)

let intervalComps = currentCalendar.components([.Day], fromDate: startDate!, toDate: endDate!, options: [])

print(intervalComps.day)

现在这一切都随着 Swift 发生了变化 3. 我必须通过不断地使用 as 进行类型转换来使用 NSCalendar 和 NSDate，或者找到 Swift 3 种方法。

在 Swift 3 中正确的做法是什么？

Answer 1

事实证明这在 Swift 3:

中要简单得多

extension Date {    

    func interval(ofComponent comp: Calendar.Component, fromDate date: Date) -> Int {

        let currentCalendar = Calendar.current

        guard let start = currentCalendar.ordinality(of: comp, in: .era, for: date) else { return 0 }
        guard let end = currentCalendar.ordinality(of: comp, in: .era, for: self) else { return 0 }

        return end - start
    }
}

编辑

比较两个日期的序数应该在同一个era内，而不是在同一个year内，因为两个日期自然可能落在不同的年份。

用法

let yesterday = Date(timeInterval: -86400, since: Date())
let tomorrow = Date(timeInterval: 86400, since: Date())


let diff = tomorrow.interval(ofComponent: .day, fromDate: yesterday)
// return 2

Answer 2

private func calculateDaysBetweenTwoDates(start: Date, end: Date) -> Int {

    let currentCalendar = Calendar.current
    guard let start = currentCalendar.ordinality(of: .day, in: .era, for: start) else {
        return 0
    }
    guard let end = currentCalendar.ordinality(of: .day, in: .era, for: end) else {
        return 0
    }
    return end - start
}

Answer 3

private func days(actual day1:[Int],expect day2:[Int]) -> Int {

    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd"
    
    let first = "\(day1[2])-\(day1[1])-\(day1[0])"
    let firstDate = dateFormatter.date(from:first)!
    let last = "\(day2[2])-\(day2[1])-\(day2[0])"
    let lastDate = dateFormatter.date(from:last)!
    
    let currentCalendar = NSCalendar.current
    
    let components = currentCalendar.dateComponents([.day], from: firstDate, to: lastDate)
    
    return components.day!
}

另一种比较日月年分量的方法

用法：

按以下格式输入日期

[dd, mm, yyyy]
[9, 6, 2017]
[6, 6, 2017]

Answer 4

Updated for Swift 3:

如果要打印天数以及两个日历日期之间的天数列表，请使用下面的简单代码；

//变量声明：

var daysListArray = [String]()

// 函数定义：

func printCountBtnTwoDates(mStartDate: Date, mEndDate: Date) -> Int {
    let calendar = Calendar.current
    let formatter = DateFormatter()
    var newDate = mStartDate
    daysListArray.removeAll()

    while newDate <= mEndDate {
        formatter.dateFormat = "yyyy-MM-dd"
        daysListArray.append(formatter.string(from: newDate))
        newDate = calendar.date(byAdding: .day, value: 1, to: newDate)!
    }
   // print("daysListArray: \(daysListArray)") // if you want to print list between start date and end date
    return daysListArray.count
}

// 调用上面的函数：

    let count = self.printCountBtnTwoDates(mStartDate: your_start_date, mEndDate: your_end_date)
    print("count: \(count)") // date count

// 享受编码...！

Answer 5

在 Swift4 中，我们可以使用以下代码轻松获取两个不同日历日期之间的天数。

第一个是与当前日期的天数差异。

let previousDate = "2017-03-01"
let currentDate = Date()
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let previousDateFormated : Date? = dateFormatter.date(from: previousDate)
let difference = currentDate.timeIntervalSince(previousDateFormated!)
var differenceInDays = Int(difference/(60 * 60 * 24 ))
print(differenceInDays)

继续上面的代码...下面是查找两个不同日期的天数。前一个日期的内容取自上面的日期

let futureDate = "2017-12-30"
let futureDateFormatted : Date? = dateFormatter.date(from: futureDate)
differenceInDays = (futureDateFormatted?.timeIntervalSince(previousDateFormated!))! / (60 * 60 * 24)

print(differenceInDays)

Answer 6

Swift 4 版本

let startDate = "2000-11-22"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let formatedStartDate = dateFormatter.date(from: startDate)
let currentDate = Date()
let components = Set<Calendar.Component>([.second, .minute, .hour, .day, .month, .year])
let differenceOfDate = Calendar.current.dateComponents(components, from: formatedStartDate!, to: currentDate)

print (differenceOfDate)

印刷- 年：16 月：10 日：19 时：12 分：16 秒：42 isLeapMonth: false

swift4 calendar date

Answer 7

在 Swift 5 中有一个简单的一行代码来获取两个日期之间的天数（或任何其他 DateComponent）：

let diffInDays = Calendar.current.dateComponents([.day], from: dateA, to: dateB).day

注意：正如评论中所指出的，此解决方案测量的是 24 小时周期，因此在 dateA 和 dateB 之间至少需要 24 小时。

Answer 8

在不同的线程上找到这个，但它最终是我使用 Swift 4:

的最简单的解决方案

let previousDate = ENTER DATE HERE
let now = Date()

let formatter = DateComponentsFormatter()
formatter.unitsStyle = .brief // May delete the word brief to let Xcode show you the other options
formatter.allowedUnits = [.month, .day, .hour]
formatter.maximumUnitCount = 1   // Show just one unit (i.e. 1d vs. 1d 6hrs)

let stringDate = formatter.string(from: previousDate, to: now)

Answer 9

如果有人想更具体地执行以下步骤

1.Add 这个日期延期

extension Date {
    /// Returns the amount of years from another date
func years(from date: Date) -> Int {
    return Calendar.current.dateComponents([.year], from: date, to: self).year ?? 0
}
/// Returns the amount of months from another date
func months(from date: Date) -> Int {
    return Calendar.current.dateComponents([.month], from: date, to: self).month ?? 0
}
/// Returns the amount of weeks from another date
func weeks(from date: Date) -> Int {
    return Calendar.current.dateComponents([.weekOfMonth], from: date, to: self).weekOfMonth ?? 0
}
/// Returns the amount of days from another date
func days(from date: Date) -> Int {
    return Calendar.current.dateComponents([.day], from: date, to: self).day ?? 0
}
/// Returns the amount of hours from another date
func hours(from date: Date) -> Int {
    return Calendar.current.dateComponents([.hour], from: date, to: self).hour ?? 0
}
/// Returns the amount of minutes from another date
func minutes(from date: Date) -> Int {
    return Calendar.current.dateComponents([.minute], from: date, to: self).minute ?? 0
}
/// Returns the amount of seconds from another date
func seconds(from date: Date) -> Int {
    return Calendar.current.dateComponents([.second], from: date, to: self).second ?? 0
}
/// Returns the amount of nanoseconds from another date
func nanoseconds(from date: Date) -> Int {
    return Calendar.current.dateComponents([.nanosecond], from: date, to: self).nanosecond ?? 0
}
/// Returns the a custom time interval description from another date
func offset(from date: Date) -> String {
    var result: String = ""
            if years(from: date)   > 0 { return "\(years(from: date))y"   }
            if months(from: date)  > 0 { return "\(months(from: date))M"  }
            if weeks(from: date)   > 0 { return "\(weeks(from: date))w"   }
    if seconds(from: date) > 0 { return "\(seconds(from: date))" }
            if days(from: date)    > 0 { result = result + " " + "\(days(from: date)) D" }
            if hours(from: date)   > 0 { result = result + " " + "\(hours(from: date)) H" }
            if minutes(from: date) > 0 { result = result + " " + "\(minutes(from: date)) M" }
           if seconds(from: date) > 0 { return "\(seconds(from: date))" }
    return ""
 }
}

2.Define 它在全球范围内

 fileprivate var timer: Timer?

3.Call 这个方法在 viewDidLoad 或任何你想要的地方

override func viewDidLoad() {
    super.viewDidLoad()
    self.getRemainingTime()
}

4.Usage

fileprivate func getRemainingTime() {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"

    let startDate = "2018-06-02 10:11:12"
    let currentDate = dateFormatter.string(from: Date())

    if currentDate != startDate {
        timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(calculateTime)), userInfo: nil, repeats: true)
        RunLoop.current.add(timer!, forMode: RunLoopMode.commonModes)
        timer?.fire()
    }
    else {
        self.timer?.invalidate()
        self.timer = nil
    }
}

func calculateTime() {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"

    let stdate : String = "2018-06-02 10:11:12"
    let startDate = dateFormatter.date(from: stdate)!

    let currentDate = Date()

    let strTimer : String = startDate.offset(from: currentDate)
    if !strTimer.isEmpty {
        let stDay: String = "\((Int(strTimer)! % 31536000) / 86400)"
        let stHour: String = "\((Int(strTimer)! % 86400) / 3600)"
        let stMin: String = "\((Int(strTimer)! % 3600) / 60)"
        let stSec: String = "\(Int(strTimer)! % 60)"
        yourLabelOutlet.text = "Start In :\(stDay) Days \(stHour) Hours \(stMin) Minutes \(stSec) Seconds"
    }

}

像魅力一样工作您可以在 UI 端使用每个单独的字符串，享受

Answer 10

如果有人需要显示所有时间单位，例如 "hours minutes seconds" 而不仅仅是 "hours"。假设两个日期之间的时差是 1 小时 59 分 20 秒。此函数将显示“1h 59m 20s”。

这是我的代码：

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'hh:mm:ss"
let start = dateFormatter.date(from: "2019-01-31T07:45:00")!
let end = dateFormatter.date(from: "2019-03-01T06:30:00")!
print("Date Difference :   ", end.offsetFrom(date: start))

函数定义：

extension Date {

    func offsetFrom(date : Date) -> String {

        let dayHourMinuteSecond: Set = [.day, .hour, .minute, .second]
        let difference = NSCalendar.current.dateComponents(dayHourMinuteSecond, from: date, to: self);

        let seconds = "\(difference.second ?? 0)s"
        let minutes = "\(difference.minute ?? 0)m" + " " + seconds
        let hours = "\(difference.hour ?? 0)h" + " " + minutes
        let days = "\(difference.day ?? 0)d" + " " + hours

        if let day = difference.day, day          > 0 { return days }
        if let hour = difference.hour, hour       > 0 { return hours }
        if let minute = difference.minute, minute > 0 { return minutes }
        if let second = difference.second, second > 0 { return seconds }
        return ""
    }
}

Answer 11

import Foundation

extension DateComponents {

    func dateComponentsToTimeString() -> String {

        var hour = "\(self.hour!)"
        var minute = "\(self.minute!)"
        var second = "\(self.second!)"

        if self.hour! < 10 { hour = "0" + hour }
        if self.minute! < 10 { minute = "0" + minute }
        if self.second! < 10 { second = "0" + second }

        let str = "\(hour):\(minute):\(second)"
        return str
    }

}

extension Date {

    func offset(from date: Date)-> DateComponents {
        let components = Set<Calendar.Component>([.second, .minute, .hour, .day, .month, .year])
        let differenceOfDate = Calendar.current.dateComponents(components, from: date, to: self)
        return differenceOfDate
    }
}

使用：

 var durationString: String {
        return self.endTime.offset(from: self.startTime).dateComponentsToTimeString()
    }

Swift 3 - 查找两个日期之间的日历天数

Swift 3 - find number of calendar days between two dates

nsdate

nscalendar

swift3