Swift 3 - 查找两个日期之间的日历天数

问题描述 投票：0回答：10

我在 Swift 2.3 中这样做的方式是：

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 3 的改变而改变了。我必须通过不断地使用 

NSCalendar
进行类型转换来使用 
NSDate
和 
as
，或者找到 Swift 3 的方法来做到这一点。

在 Swift 3 中正确的做法是什么？

nsdate swift3 nscalendar
10个回答
120
投票

在 Swift 5 中，有一个简单的单行代码可以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，该解决方案测量 24 小时周期，因此需要在 

dateA
和 
dateB
之间至少有 24 小时。

57
投票

事实证明，在 Swift 3 中这要简单得多：

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相同的

era
内，而不是相同的
year
，因为两个日期自然可能属于不同的年份。

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
23
投票

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 天：19 小时：12 分钟：16 秒：42 isLeapMonth：false

9
投票
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
}
7
投票

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)
3
投票

如果有人需要显示所有时间单位，例如“小时分钟秒”而不仅仅是“小时”。假设两个日期之间的时差为 1 小时 59 分 20 秒。此功能将显示“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 ""
    }
}
3
投票

在不同的线程上找到了这个，但它最终是我使用 Swift 4 最简单的解决方案：

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

let formatter = DateComponentsFormatter()
formatter.unitsStyle = .brief // or other options
formatter.allowedUnits = [.month, .day, .hour]
formatter.maximumUnitCount = 1   // Show one unit, eg 1d vs. 1d 6hrs)

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

这将为您提供一个结果，例如 

2m
（两个月前）或 
7h
（）七小时前）。请注意，您可以简单地改为

formatter.allowedUnits = [.day]

这将给它几天的时间，例如

71d
或
0d
。

1
投票
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
    }
}

用途：

 var durationString: String {
        return self.endTime.offset(from: self.startTime).dateComponentsToTimeString()
    }
0
投票

更新为 Swift 3：

如果要打印两个日历日期之间的天数以及天数列表，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

// 享受编码的乐趣...！

0
投票
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!
}

与日月年的组成部分进行比较的另一种方法

用途：

按照以下格式输入日期

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