blocks|key|92337|text|swift内置的东西仍然是非常基础的。就像他们在早期阶段应该做的那样。但是你可以添加你自己的东西，这会带来重载运算符和全局域函数的风险。不过，它们对于您的模块来说是本地的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92338|let+now+=+NSDate()
let+seventies+=+NSDate(timeIntervalSince1970:+0)

//+Standard+solution+still+works
let+days+=+NSCalendar.currentCalendar().components(.CalendarUnitDay,+
+++++++++++fromDate:+seventies,+toDate:+now,+options:+nil).day

//+Flashy+swift...+maybe...
func+-(lhs:NSDate,+rhs:NSDate)+->+DateRange+{
++++return+DateRange(startDate:+rhs,+endDate:+lhs)
}

class+DateRange+{
++++let+startDate:NSDate
++++let+endDate:NSDate
++++var+calendar+=+NSCalendar.currentCalendar()
++++var+days:+Int+{
++++++++return+calendar.components(.CalendarUnitDay,+
+++++++++++++++fromDate:+startDate,+toDate:+endDate,+options:+nil).day
++++}
++++var+months:+Int+{
++++++++return+calendar.components(.CalendarUnitMonth,+
+++++++++++++++fromDate:+startDate,+toDate:+endDate,+options:+nil).month
++++}
++++init(startDate:NSDate,+endDate:NSDate)+{
++++++++self.startDate+=+startDate
++++++++self.endDate+=+endDate
++++}
}

//+Now+you+can+do+this...
(now+-+seventies).months
(now+-+seventies).days|code-block|syntax|javascript|92339|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The things built into swift are still very basic. As they should be at this early stage. But you can add your own stuff with the risk that comes with overloading operators and global domain functions. They will be local to your module though.

<pre><code>let now = NSDate()
let seventies = NSDate(timeIntervalSince1970: 0)

// Standard solution still works
let days = NSCalendar.currentCalendar().components(.CalendarUnitDay, 
 fromDate: seventies, toDate: now, options: nil).day

// Flashy swift... maybe...
func -(lhs:NSDate, rhs:NSDate) -&gt; DateRange {
 return DateRange(startDate: rhs, endDate: lhs)
}

class DateRange {
 let startDate:NSDate
 let endDate:NSDate
 var calendar = NSCalendar.currentCalendar()
 var days: Int {
 return calendar.components(.CalendarUnitDay, 
 fromDate: startDate, toDate: endDate, options: nil).day
 }
 var months: Int {
 return calendar.components(.CalendarUnitMonth, 
 fromDate: startDate, toDate: endDate, options: nil).month
 }
 init(startDate:NSDate, endDate:NSDate) {
 self.startDate = startDate
 self.endDate = endDate
 }
}

// Now you can do this...
(now - seventies).months
(now - seventies).days
</code></pre>

blocks|key|4598460|text|目前还几乎没有任何特定于Swift的标准库；只有精简的基本数字、字符串和集合类型。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4598461|使用扩展来定义这样的速记是完全可能的，但是就实际的开箱即用的API而言，并没有“新的”Cocoa；Swift只是直接映射到已经存在的相同的冗长的Cocoa+API。|4598462|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

There's hardly any Swift-specific standard library yet; just the lean basic numeric, string, and collection types.

It's perfectly possible to define such shorthands using extensions, but as far as the actual out-of-the-box APIs goes, there is no "new" Cocoa; Swift just maps directly to the same old verbose Cocoa APIs as they already exist.

blocks|key|92388|text|我翻译了我的Objective-C+answer|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|92389|let+start+=+"2010-09-01"
let+end+=+"2010-09-05"

let+dateFormatter+=+NSDateFormatter()
dateFormatter.dateFormat+=+"yyyy-MM-dd"

let+startDate:NSDate+=+dateFormatter.dateFromString(start)
let+endDate:NSDate+=+dateFormatter.dateFromString(end)

let+cal+=+NSCalendar.currentCalendar()


let+unit:NSCalendarUnit+=+.Day

let+components+=+cal.components(unit,+fromDate:+startDate,+toDate:+endDate,+options:+nil)


println(components)|code-block|syntax|javascript|92390|结果|92391|<NSDateComponents:+0x10280a8a0>
+++++Day:+4|92392|最困难的部分是自动补全坚持fromDate和toDate将是NSDate?，但实际上它们必须是NSDate!，如参考资料所示。|style|CODE|92393|我看不出使用运算符的好的解决方案是什么样子，因为您希望在每种情况下指定不同的单位。您可以返回时间间隔，但您不会获得太多。|92394|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/4576575/106435^0|6|I|0|0|0|0|0|U|7|1B|7|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@$A|11|B|12|1|13]]|C|$]]|$1|D|3|E|5|F|7|14|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|15|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|16|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|17|8|@$A|18|B|19|O|P]|$A|1A|B|1B|O|P]]|9|@]|C|$]]|$1|Q|3|R|5|6|7|1C|8|@]|9|@]|C|$]]|$1|S|3|-4|5|6|7|1D|8|@]|9|@]|C|$]]]|T|$U|$5|V|W|X|C|$Y|Z]]]]

I translated my <a href="https://stackoverflow.com/a/4576575/106435">Objective-C answer</a>

<pre><code>let start = "2010-09-01"
let end = "2010-09-05"

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"

let startDate:NSDate = dateFormatter.dateFromString(start)
let endDate:NSDate = dateFormatter.dateFromString(end)

let cal = NSCalendar.currentCalendar()


let unit:NSCalendarUnit = .Day

let components = cal.components(unit, fromDate: startDate, toDate: endDate, options: nil)


println(components)
</code></pre>

result 

<pre><code>&lt;NSDateComponents: 0x10280a8a0&gt;
 Day: 4
</code></pre>

The hardest part was that the autocompletion insists fromDate and toDate would be <code>NSDate?</code>, but indeed they must be <code>NSDate!</code> as shown in the reference. 

I don't see how a good solution with an operator would look like, as you want to specify the unit differently in each case. You could return the time interval, but than won't you gain much.

blocks|key|4598531|text|你还得考虑时差。例如，如果比较日期2015-01-01+10:00和2015-01-02+09:00，则这两个日期之间的天数将返回0(零)，因为这两个日期之间的差值小于24小时(+23小时)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4598532|如果您的目的是获取两个日期之间的确切天数，则可以像这样解决此问题：|4598533|//+Assuming+that+firstDate+and+secondDate+are+defined
//+...

let+calendar+=+NSCalendar.currentCalendar()

//+Replace+the+hour+(time)+of+both+dates+with+00:00
let+date1+=+calendar.startOfDayForDate(firstDate)
let+date2+=+calendar.startOfDayForDate(secondDate)

let+flags+=+NSCalendarUnit.Day
let+components+=+calendar.components(flags,+fromDate:+date1,+toDate:+date2,+options:+[])

components.day++//+This+will+return+the+number+of+day(s)+between+dates|code-block|syntax|javascript|4598534|Swift+3和Swift+4版本|4598535|let+calendar+=+Calendar.current

//+Replace+the+hour+(time)+of+both+dates+with+00:00
let+date1+=+calendar.startOfDay(for:+firstDate)
let+date2+=+calendar.startOfDay(for:+secondDate)

let+components+=+calendar.dateComponents([.day],+from:+date1,+to:+date2)|4598536|entityMap^0|H|G|Y|G|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|Z|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

You have to consider the time difference as well. For example if you compare the dates <code>2015-01-01 10:00</code> and <code>2015-01-02 09:00</code>, days between those dates will return as 0 (zero) since the difference between those dates is less than 24 hours (it's 23 hours).

If your purpose is to get the exact day number between two dates, you can work around this issue like this: 

<pre><code>// Assuming that firstDate and secondDate are defined
// ...

let calendar = NSCalendar.currentCalendar()

// Replace the hour (time) of both dates with 00:00
let date1 = calendar.startOfDayForDate(firstDate)
let date2 = calendar.startOfDayForDate(secondDate)

let flags = NSCalendarUnit.Day
let components = calendar.components(flags, fromDate: date1, toDate: date2, options: [])

components.day // This will return the number of day(s) between dates
</code></pre>

<h2>Swift 3 and Swift 4 Version</h2>

<pre><code>let calendar = Calendar.current

// Replace the hour (time) of both dates with 00:00
let date1 = calendar.startOfDay(for: firstDate)
let date2 = calendar.startOfDay(for: secondDate)

let components = calendar.dateComponents([.day], from: date1, to: date2)
</code></pre>

blocks|key|4598555|text|我要添加我的版本，即使这个线程已经存在一年了。我的代码如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4598556|++++var+name+=+txtName.stringValue+//+Get+the+users+name

++++//+Get+the+date+components+from+the+window+controls
++++var+dateComponents+=+NSDateComponents()
++++dateComponents.day+=+txtDOBDay.integerValue
++++dateComponents.month+=+txtDOBMonth.integerValue
++++dateComponents.year+=+txtDOBYear.integerValue

++++//+Make+a+Gregorian+calendar
++++let+calendar+=+NSCalendar(identifier:+NSCalendarIdentifierGregorian)

++++//+Get+the+two+dates+we+need
++++var+birthdate+=+calendar?.dateFromComponents(dateComponents)
++++let+currentDate+=+NSDate()

++++var+durationDateComponents+=+calendar?.components(NSCalendarUnit.CalendarUnitDay,+fromDate:+birthdate!,+toDate:+currentDate,+options:+nil)

++++let+numberOfDaysAlive+=+durationDateComponents?.day

++++println("\(numberOfDaysAlive!)")

++++txtGreeting.stringValue+=+"Hello+\(name),+You+have+been+alive+for+\(numberOfDaysAlive!)+days."|code-block|syntax|javascript|4598557|我希望它能帮助一些人。|4598558|干杯,|4598559|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I'm going to add my version even though this thread is a year old. My code looks like this:

<pre><code> var name = txtName.stringValue // Get the users name

 // Get the date components from the window controls
 var dateComponents = NSDateComponents()
 dateComponents.day = txtDOBDay.integerValue
 dateComponents.month = txtDOBMonth.integerValue
 dateComponents.year = txtDOBYear.integerValue

 // Make a Gregorian calendar
 let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)

 // Get the two dates we need
 var birthdate = calendar?.dateFromComponents(dateComponents)
 let currentDate = NSDate()

 var durationDateComponents = calendar?.components(NSCalendarUnit.CalendarUnitDay, fromDate: birthdate!, toDate: currentDate, options: nil)

 let numberOfDaysAlive = durationDateComponents?.day

 println("\(numberOfDaysAlive!)")

 txtGreeting.stringValue = "Hello \(name), You have been alive for \(numberOfDaysAlive!) days."
</code></pre>

I hope it helps someone.

Cheers,

blocks|key|92474|text|以下是我对Swift+2的回答：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92475|func+daysBetweenDates(startDate:+NSDate,+endDate:+NSDate)+->+Int
{
++++let+calendar+=+NSCalendar.currentCalendar()

++++let+components+=+calendar.components([.Day],+fromDate:+startDate,+toDate:+endDate,+options:+[])

++++return+components.day
}|code-block|syntax|javascript|92476|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here is my answer for Swift 2:

<pre><code>func daysBetweenDates(startDate: NSDate, endDate: NSDate) -&gt; Int
{
 let calendar = NSCalendar.currentCalendar()

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

 return components.day
}
</code></pre>

blocks|key|4598599|text|let+calendar+=+NSCalendar.currentCalendar();
let+component1+=+calendar.component(.Day,+fromDate:+fromDate)
let+component2+=+calendar.component(.Day,+fromDate:+toDate)
let+difference++=+component1+-+component2|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4598600|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>let calendar = NSCalendar.currentCalendar();
let component1 = calendar.component(.Day, fromDate: fromDate)
let component2 = calendar.component(.Day, fromDate: toDate)
let difference = component1 - component2
</code></pre>

blocks|key|92517|text|以下是Swift+3的答案(针对IOS+10测试版进行测试)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92518|func+daysBetweenDates(startDate:+Date,+endDate:+Date)+->+Int
{
++++let+calendar+=+Calendar.current
++++let+components+=+calendar.components([.day],+from:+startDate,+to:+endDate,+options:+[])
++++return+components.day!
}|code-block|syntax|javascript|92519|然后你可以这样叫它|92520|let+pickedDate:+Date+=+sender.date
let+NumOfDays:+Int+=+daysBetweenDates(startDate:+pickedDate,+endDate:+Date())
++++print("Num+of+Days:+\(NumOfDays)")|92521|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Here is the answer for Swift 3 (tested for IOS 10 Beta)

<pre><code>func daysBetweenDates(startDate: Date, endDate: Date) -&gt; Int
{
 let calendar = Calendar.current
 let components = calendar.components([.day], from: startDate, to: endDate, options: [])
 return components.day!
}
</code></pre>

Then you can call it like this

<pre><code>let pickedDate: Date = sender.date
let NumOfDays: Int = daysBetweenDates(startDate: pickedDate, endDate: Date())
 print("Num of Days: \(NumOfDays)")
</code></pre>

blocks|key|92542|text|Swift+3+iOS+10+Beta+4更新|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92543|func+daysBetweenDates(startDate:+Date,+endDate:+Date)+->+Int+{
++++let+calendar+=+Calendar.current
++++let+components+=+calendar.dateComponents([Calendar.Component.day],+from:+startDate,+to:+endDate)
++++return+components.day!
}|code-block|syntax|javascript|92544|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Update for Swift 3 iOS 10 Beta 4

<pre><code>func daysBetweenDates(startDate: Date, endDate: Date) -&gt; Int {
 let calendar = Calendar.current
 let components = calendar.dateComponents([Calendar.Component.day], from: startDate, to: endDate)
 return components.day!
}
</code></pre>

blocks|key|4598707|text|我看到了几个Swift3答案，所以我将添加我自己的答案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4598708|public+static+func+daysBetween(start:+Date,+end:+Date)+->+Int+{
+++Calendar.current.dateComponents([.day],+from:+start,+to:+end).day!
}|code-block|syntax|javascript|4598709|命名感觉更快，只有一行，并且使用了最新的dateComponents()方法。|offset|length|style|CODE|4598710|entityMap^0|0|0|K|G|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I see a couple Swift3 answers so I'll add my own:
<pre><code>public static func daysBetween(start: Date, end: Date) -&gt; Int {
 Calendar.current.dateComponents([.day], from: start, to: end).day!
}
</code></pre>
The naming feels more Swifty, it's one line, and using the latest <code>dateComponents()</code> method.

blocks|key|92689|text|Erin的方法更新到Swift+3，这显示从今天开始的天数(忽略一天中的时间)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92690|func+daysBetweenDates(+endDate:+Date)+->+Int+
++++let+calendar:+Calendar+=+Calendar.current+
++++let+date1+=+calendar.startOfDay(for:+Date())+
++++let+date2+=+calendar.startOfDay(for:+secondDate)+
++++return+calendar.dateComponents([.day],+from:+date1,+to:+date2).day!+
}|code-block|syntax|javascript|92691|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Erin's method updated to Swift 3, This shows days from today (disregarding time of day)

<pre><code>func daysBetweenDates( endDate: Date) -&gt; Int 
 let calendar: Calendar = Calendar.current 
 let date1 = calendar.startOfDay(for: Date()) 
 let date2 = calendar.startOfDay(for: secondDate) 
 return calendar.dateComponents([.day], from: date1, to: date2).day! 
}
</code></pre>

blocks|key|92720|text|以下是我对Swift+3的回答：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92721|func+daysBetweenDates(startDate:+NSDate,+endDate:+NSDate,+inTimeZone+timeZone:+TimeZone?+=+nil)+->+Int+{
++++var+calendar+=+Calendar.current
++++if+let+timeZone+=+timeZone+{
++++++++calendar.timeZone+=+timeZone
++++}
++++let+dateComponents+=+calendar.dateComponents([.day],+from:+startDate.startOfDay,+to:+endDate.startOfDay)
++++return+dateComponents.day!
}|code-block|syntax|javascript|92722|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here is my answer for Swift 3:

<pre><code>func daysBetweenDates(startDate: NSDate, endDate: NSDate, inTimeZone timeZone: TimeZone? = nil) -&gt; Int {
 var calendar = Calendar.current
 if let timeZone = timeZone {
 calendar.timeZone = timeZone
 }
 let dateComponents = calendar.dateComponents([.day], from: startDate.startOfDay, to: endDate.startOfDay)
 return dateComponents.day!
}
</code></pre>

blocks|key|92770|text|Swift+3天-从今天到日期|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92771|func+daysUntilDate(endDateComponents:+DateComponents)+->+Int
++++{
++++++++let+cal+=+Calendar.current
++++++++var+components+=+cal.dateComponents([.era,+.year,+.month,+.day],+from:+NSDate()+as+Date)
++++++++let+today+=+cal.date(from:+components)
++++++++let+otherDate+=+cal.date(from:+endDateComponents)

++++++++components+=+cal.dateComponents([Calendar.Component.day],+from:+(today!+as+Date),+to:+otherDate!)
++++++++return+components.day!
++++}|code-block|syntax|javascript|92772|像这样调用函数|92773|//+Days+from+today+until+date
+++var+examnDate+=+DateComponents()
+++examnDate.year+=+2016
+++examnDate.month+=+12
+++examnDate.day+=+15
+++let+daysCount+=+daysUntilDate(endDateComponents:+examnDate)|92774|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Swift 3 - Days from today until date

<pre><code>func daysUntilDate(endDateComponents: DateComponents) -&gt; Int
 {
 let cal = Calendar.current
 var components = cal.dateComponents([.era, .year, .month, .day], from: NSDate() as Date)
 let today = cal.date(from: components)
 let otherDate = cal.date(from: endDateComponents)

 components = cal.dateComponents([Calendar.Component.day], from: (today! as Date), to: otherDate!)
 return components.day!
 }
</code></pre>

Call function like this

<pre><code>// Days from today until date
 var examnDate = DateComponents()
 examnDate.year = 2016
 examnDate.month = 12
 examnDate.day = 15
 let daysCount = daysUntilDate(endDateComponents: examnDate)
</code></pre>

blocks|key|4598905|text|更简单的选择是在日期上创建一个延期|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4598906|public+extension+Date+{

++++++++public+var+currentCalendar:+Calendar+{
++++++++++++return+Calendar.autoupdatingCurrent
++++++++}

++++++++public+func+daysBetween(_+date:+Date)+->+Int+{
++++++++++++let+components+=+currentCalendar.dateComponents([.day],+from:+self,+to:+date)
++++++++++++return+components.day!
++++++++}
++++}|code-block|syntax|javascript|4598907|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

easier option would be to create a extension on Date

<pre><code>public extension Date {

 public var currentCalendar: Calendar {
 return Calendar.autoupdatingCurrent
 }

 public func daysBetween(_ date: Date) -&gt; Int {
 let components = currentCalendar.dateComponents([.day], from: self, to: date)
 return components.day!
 }
 }
</code></pre>

blocks|key|92850|text|Swift+5.感谢上面startOfDay的建议。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|92851|extension+Date+{
++++
++++func+daysBetween(date:+Date)+->+Int+{
++++++++return+Date.daysBetween(start:+self,+end:+date)
++++}
++++
++++static+func+daysBetween(start:+Date,+end:+Date)+->+Int+{
++++++++let+calendar+=+Calendar.current
++++++++
++++++++//+Replace+the+hour+(time)+of+both+dates+with+00:00
++++++++let+date1+=+calendar.startOfDay(for:+start)
++++++++let+date2+=+calendar.startOfDay(for:+end)
++++++++
++++++++let+a+=+calendar.dateComponents([.day],+from:+date1,+to:+date2)
++++++++return+a.value(for:+.day)!
++++}
}|code-block|syntax|javascript|92852|用法：|92853|let+dateFormatter+=+DateFormatter()
dateFormatter.dateFormat+=+"yyyy-MM-dd"
let+start+=+dateFormatter.date(from:+"2017-01-01")!
let+end+=+dateFormatter.date(from:+"2018-01-01")!

let+diff+=+Date.daysBetween(start:+start,+end:+end)+//+365
//+or
let+diff+=+start.daysBetween(date:+end)+//+365|92854|entityMap^0|C|A|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

Swift 5. Thanks to <a href="https://stackoverflow.com/users/1437254/emin-bu%C4%9Fra-saral/" title="Emin">Emin Buğra Saral</a> above for the <code>startOfDay</code> suggestion.
<pre><code>extension Date {
 
 func daysBetween(date: Date) -&gt; Int {
 return Date.daysBetween(start: self, end: date)
 }
 
 static func daysBetween(start: Date, end: Date) -&gt; Int {
 let calendar = Calendar.current
 
 // Replace the hour (time) of both dates with 00:00
 let date1 = calendar.startOfDay(for: start)
 let date2 = calendar.startOfDay(for: end)
 
 let a = calendar.dateComponents([.day], from: date1, to: date2)
 return a.value(for: .day)!
 }
}
</code></pre>
Usage:
<pre><code>let dateFormatter = DateFormatter()
dateFormatter.dateFormat = &quot;yyyy-MM-dd&quot;
let start = dateFormatter.date(from: &quot;2017-01-01&quot;)!
let end = dateFormatter.date(from: &quot;2018-01-01&quot;)!

let diff = Date.daysBetween(start: start, end: end) // 365
// or
let diff = start.daysBetween(date: end) // 365
</code></pre>

blocks|key|92881|text|Swift+3.2|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92882|extension+DateComponentsFormatter+{
++++func+difference(from+fromDate:+Date,+to+toDate:+Date)+->+String?+{
++++++++self.allowedUnits+=+[.year,.month,.weekOfMonth,.day]
++++++++self.maximumUnitCount+=+1
++++++++self.unitsStyle+=+.full
++++++++return+self.string(from:+fromDate,+to:+toDate)
++++}
}|code-block|syntax|javascript|92883|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Swift 3.2

<pre><code>extension DateComponentsFormatter {
 func difference(from fromDate: Date, to toDate: Date) -&gt; String? {
 self.allowedUnits = [.year,.month,.weekOfMonth,.day]
 self.maximumUnitCount = 1
 self.unitsStyle = .full
 return self.string(from: fromDate, to: toDate)
 }
}
</code></pre>

blocks|key|4598999|text|2017版本，复制粘贴|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4599000|func+simpleIndex(ofDate:+Date)+->+Int+{
++++
++++//+index+here+just+means+today+0,+yesterday+-1,+tomorrow+1+etc.
++++
++++let+c+=+Calendar.current
++++let+todayRightNow+=+Date()
++++
++++let+d+=+c.date(bySetting:+.hour,+value:+13,+of:+ofDate)
++++let+t+=+c.date(bySetting:+.hour,+value:+13,+of:+todayRightNow)
++++
++++if+d+==+nil+%7C%7C+today+==+nil+{
++++
++++++++print("weird+problem+simpleIndex#ofDate")
++++++++return+0
++++}
++++
++++let+r+=+c.dateComponents([.day],+from:+today!,+to:+d!)
++++//+yesterday+is+negative+one,+tomorrow+is+one
++++
++++if+let+o+=+r.value(for:+.day)+{
++++++++
++++++++return+o
++++}
++++else+{
++++
++++++++print("another+weird+problem+simpleIndex#ofDate")
++++++++return+0
++++}
}|code-block|syntax|javascript|4599001|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<h1>2017 version, copy and paste</h1>
<pre><code>func simpleIndex(ofDate: Date) -&gt; Int {
 
 // index here just means today 0, yesterday -1, tomorrow 1 etc.
 
 let c = Calendar.current
 let todayRightNow = Date()
 
 let d = c.date(bySetting: .hour, value: 13, of: ofDate)
 let t = c.date(bySetting: .hour, value: 13, of: todayRightNow)
 
 if d == nil || today == nil {
 
 print(&quot;weird problem simpleIndex#ofDate&quot;)
 return 0
 }
 
 let r = c.dateComponents([.day], from: today!, to: d!)
 // yesterday is negative one, tomorrow is one
 
 if let o = r.value(for: .day) {
 
 return o
 }
 else {
 
 print(&quot;another weird problem simpleIndex#ofDate&quot;)
 return 0
 }
}
</code></pre>

blocks|key|92970|text|这是一个非常好的Date扩展，可以在年、月、日、小时、分钟、秒中获取日期的差异|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|92971|extension+Date+{

++++func+years(sinceDate:+Date)+->+Int?+{
++++++++return+Calendar.current.dateComponents([.year],+from:+sinceDate,+to:+self).year
++++}

++++func+months(sinceDate:+Date)+->+Int?+{
++++++++return+Calendar.current.dateComponents([.month],+from:+sinceDate,+to:+self).month
++++}

++++func+days(sinceDate:+Date)+->+Int?+{
++++++++return+Calendar.current.dateComponents([.day],+from:+sinceDate,+to:+self).day
++++}

++++func+hours(sinceDate:+Date)+->+Int?+{
++++++++return+Calendar.current.dateComponents([.hour],+from:+sinceDate,+to:+self).hour
++++}

++++func+minutes(sinceDate:+Date)+->+Int?+{
++++++++return+Calendar.current.dateComponents([.minute],+from:+sinceDate,+to:+self).minute
++++}

++++func+seconds(sinceDate:+Date)+->+Int?+{
++++++++return+Calendar.current.dateComponents([.second],+from:+sinceDate,+to:+self).second
++++}

}|code-block|syntax|javascript|92972|entityMap^0|8|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Here is very nice, <code>Date</code> extension to get difference between dates in years, months, days, hours, minutes, seconds

<pre><code>extension Date {

 func years(sinceDate: Date) -&gt; Int? {
 return Calendar.current.dateComponents([.year], from: sinceDate, to: self).year
 }

 func months(sinceDate: Date) -&gt; Int? {
 return Calendar.current.dateComponents([.month], from: sinceDate, to: self).month
 }

 func days(sinceDate: Date) -&gt; Int? {
 return Calendar.current.dateComponents([.day], from: sinceDate, to: self).day
 }

 func hours(sinceDate: Date) -&gt; Int? {
 return Calendar.current.dateComponents([.hour], from: sinceDate, to: self).hour
 }

 func minutes(sinceDate: Date) -&gt; Int? {
 return Calendar.current.dateComponents([.minute], from: sinceDate, to: self).minute
 }

 func seconds(sinceDate: Date) -&gt; Int? {
 return Calendar.current.dateComponents([.second], from: sinceDate, to: self).second
 }

}
</code></pre>

blocks|key|4599134|text|所有的答案都是好的。但是对于本地化，我们需要计算两个日期之间的十进制天数。因此，我们可以提供可持续的小数格式。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4599135|//+This+method+returns+the+fractional+number+of+days+between+to+dates
func+getFractionalDaysBetweenDates(date1:+Date,+date2:+Date)+->+Double+{

++++let+components+=+Calendar.current.dateComponents([.day,+.hour],+from:+date1,+to:+date2)

++++var+decimalDays+=+Double(components.day!)
++++decimalDays+%2B=+Double(components.hour!)+/+24.0

++++return+decimalDays
}|code-block|syntax|javascript|4599136|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

All answer is good. But for Localizations we need calculates a number of decimal days in between two dates. so we can provide the sustainable decimal format.

<pre><code>// This method returns the fractional number of days between to dates
func getFractionalDaysBetweenDates(date1: Date, date2: Date) -&gt; Double {

 let components = Calendar.current.dateComponents([.day, .hour], from: date1, to: date2)

 var decimalDays = Double(components.day!)
 decimalDays += Double(components.hour!) / 24.0

 return decimalDays
}
</code></pre>

blocks|key|93054|text|++func+completeOffset(from+date:Date)+->+String?+{

++++let+formatter+=+DateComponentsFormatter()
++++formatter.unitsStyle+=+.brief

++++return++formatter.string(from:+Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second],+from:+date,+to:+self))




}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|93055|如果您需要年、月、日和小时作为字符串，请使用以下内容|unstyled|93056|var+tomorrow+=+Calendar.current.date(byAdding：.day，value:+1，to:+Date())！|93057|设dc+=+tomorrow.completeOffset(from:+Date())|93058|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code> func completeOffset(from date:Date) -&gt; String? {

 let formatter = DateComponentsFormatter()
 formatter.unitsStyle = .brief

 return formatter.string(from: Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second], from: date, to: self))




}
</code></pre>

if you need year month days and hours as string use this 

var tomorrow = Calendar.current.date(byAdding: .day, value: 1, to: Date())!

let dc = tomorrow.completeOffset(from: Date())

blocks|key|4599226|text|一个不错的方便的线条：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4599227|extension+Date+{
++var+daysFromNow:+Int+{
++++return+Calendar.current.dateComponents([.day],+from:+Date(),+to:+self).day!
++}
}|code-block|syntax|javascript|4599228|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Nice handy one liner :

<pre><code>extension Date {
 var daysFromNow: Int {
 return Calendar.current.dateComponents([.day], from: Date(), to: self).day!
 }
}
</code></pre>

blocks|key|93125|text|这将返回某些Date与今天的天数的绝对差异：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|93126|extension+Date+{
++func+daysFromToday()+->+Int+{
++++return+abs(Calendar.current.dateComponents([.day],+from:+self,+to:+Date()).day!)
++}
}|code-block|syntax|javascript|93127|然后使用它：|93128|if+someDate.daysFromToday()+>=+7+{
++//+at+least+a+week+from+today
}|93129|entityMap^0|6|4|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

This returns an absolute difference in days between some <code>Date</code> and today:

<pre><code>extension Date {
 func daysFromToday() -&gt; Int {
 return abs(Calendar.current.dateComponents([.day], from: self, to: Date()).day!)
 }
}
</code></pre>

and then use it:

<pre><code>if someDate.daysFromToday() &gt;= 7 {
 // at least a week from today
}
</code></pre>

blocks|key|4599296|text|extension+Date+{
++++func+daysFromToday()+->+Int+{
++++++++return+Calendar.current.dateComponents([.day],+from:+self,+to:+Date()).day!
++++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4599297|然后像这样使用它|unstyled|4599298|++++func+dayCount(dateString:+String)+->+String{
++++++++let+dateFormatter+=+DateFormatter()
++++++++dateFormatter.dateFormat+=+"MMM+dd,yyyy+hh:mm+a"
++++++++let+fetchedDate+=+dateFormatter.date(from:+dateString)


++++++++let+day+=+fetchedDate?.daysFromToday()
++++++++if+day!+>+-1{
++++++++++++return+"\(day!)+days+passed."
++++++++}else{
++++++++return+"\(day!+*+-1)+days+left."
++++++++}
++++}|4599299|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>extension Date {
 func daysFromToday() -&gt; Int {
 return Calendar.current.dateComponents([.day], from: self, to: Date()).day!
 }
}
</code></pre>

Then use it like

<pre><code> func dayCount(dateString: String) -&gt; String{
 let dateFormatter = DateFormatter()
 dateFormatter.dateFormat = "MMM dd,yyyy hh:mm a"
 let fetchedDate = dateFormatter.date(from: dateString)


 let day = fetchedDate?.daysFromToday()
 if day! &gt; -1{
 return "\(day!) days passed."
 }else{
 return "\(day! * -1) days left."
 }
 }
</code></pre>

blocks|key|4599322|text|您可以使用以下扩展：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4599323|public+extension+Date+{
++++func+daysTo(_+date:+Date)+->+Int?+{
++++++++let+calendar+=+Calendar.current

++++++++//+Replace+the+hour+(time)+of+both+dates+with+00:00
++++++++let+date1+=+calendar.startOfDay(for:+self)
++++++++let+date2+=+calendar.startOfDay(for:+date)

++++++++let+components+=+calendar.dateComponents([.day],+from:+date1,+to:+date2)
++++++++return+components.day++//+This+will+return+the+number+of+day(s)+between+dates
++++}
}|code-block|syntax|javascript|4599324|然后，你可以这样叫它：|4599325|startDate.daysTo(endDate)|4599326|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You could use the following extension:

<pre><code>public extension Date {
 func daysTo(_ date: Date) -&gt; Int? {
 let calendar = Calendar.current

 // Replace the hour (time) of both dates with 00:00
 let date1 = calendar.startOfDay(for: self)
 let date2 = calendar.startOfDay(for: date)

 let components = calendar.dateComponents([.day], from: date1, to: date2)
 return components.day // This will return the number of day(s) between dates
 }
}
</code></pre>

Then, you can call it like this:

<pre><code>startDate.daysTo(endDate)
</code></pre>

blocks|key|4599363|text|这是Emin针对Swift+5的答案的更新版本，其中包含了使用中午而不是午夜作为比较日期的最终时间的建议。它还通过返回可选的值来处理各种日期函数的潜在故障。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4599364|///
///+This+is+an+approximation;+it+does+not+account+for+time+differences.+It+will+set+the+time+to+1200+(noon)+and+provide+the+absolute+number
///+of+days+between+now+and+the+given+date.+If+the+result+is+negative,+it+should+be+read+as+"days+ago"+instead+of+"days+from+today."
///+Returns+nil+if+something+goes+wrong+initializing+or+adjusting+dates.
///

func+daysFromToday()+->+Int?
{
++++let+calendar+=+NSCalendar.current

++++//+Replace+the+hour+(time)+of+both+dates+with+noon.+(Noon+is+less+likely+to+be+affected+by+DST+changes,+timezones,+etc.+than+midnight.)
++++guard+let+date1+=+calendar.date(bySettingHour:+12,+minute:+00,+second:+00,+of:+calendar.startOfDay(for:+Date())),
++++++++++let+date2+=+calendar.date(bySettingHour:+12,+minute:+00,+second:+00,+of:+calendar.startOfDay(for:+self))+else
++++{
++++++++return+nil
++++}
++++
++++return+calendar.dateComponents([.day],+from:+date1,+to:+date2).day
}|code-block|syntax|javascript|4599365|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is an updated version of Emin's answer for Swift 5 that incorporates the suggestion to use noon instead of midnight as the definitive time for comparing days. It also handles the potential failure of various date functions by returning an optional.
<pre><code>///
/// This is an approximation; it does not account for time differences. It will set the time to 1200 (noon) and provide the absolute number
/// of days between now and the given date. If the result is negative, it should be read as &quot;days ago&quot; instead of &quot;days from today.&quot;
/// Returns nil if something goes wrong initializing or adjusting dates.
///

func daysFromToday() -&gt; Int?
{
 let calendar = NSCalendar.current

 // Replace the hour (time) of both dates with noon. (Noon is less likely to be affected by DST changes, timezones, etc. than midnight.)
 guard let date1 = calendar.date(bySettingHour: 12, minute: 00, second: 00, of: calendar.startOfDay(for: Date())),
 let date2 = calendar.date(bySettingHour: 12, minute: 00, second: 00, of: calendar.startOfDay(for: self)) else
 {
 return nil
 }
 
 return calendar.dateComponents([.day], from: date1, to: date2).day
}
</code></pre>

blocks|key|4599391|text|Swift+5.2.4解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4599392|import+UIKit

let+calendar+=+Calendar.current

let+start+=+"2010-09-01"
let+end+=+"2010-09-05"

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

let+firstDate+=+dateFormatter.date(from:+start)!
let+secondDate+=+dateFormatter.date(from:+end)!

//+Replace+the+hour+(time)+of+both+dates+with+00:00
let+date1+=+calendar.startOfDay(for:+firstDate)
let+date2+=+calendar.startOfDay(for:+secondDate)

let+components+=+calendar.dateComponents([Calendar.Component.day],+from:+date1,+to:+date2)

components.day++//+This+will+return+the+number+of+day(s)+between+dates|code-block|syntax|javascript|4599393|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Swift 5.2.4 solution:
<pre><code>import UIKit

let calendar = Calendar.current

let start = &quot;2010-09-01&quot;
let end = &quot;2010-09-05&quot;

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = &quot;yyyy-MM-dd&quot;

let firstDate = dateFormatter.date(from: start)!
let secondDate = dateFormatter.date(from: end)!

// Replace the hour (time) of both dates with 00:00
let date1 = calendar.startOfDay(for: firstDate)
let date2 = calendar.startOfDay(for: secondDate)

let components = calendar.dateComponents([Calendar.Component.day], from: date1, to: date2)

components.day // This will return the number of day(s) between dates
</code></pre>

blocks|key|4599404|text|extension+Date+{
static+func+-+(recent:+Date,+previous:+Date)+->+DateComponents+{
++++var+dateComponents+=+DateComponents()
++++dateComponents.year+=+Calendar.current.dateComponents([.day],+from:+previous,+to:+recent).year
++++dateComponents.month+=+Calendar.current.dateComponents([.month],+from:+previous,+to:+recent).month
++++dateComponents.day+=+Calendar.current.dateComponents([.day],+from:+previous,+to:+recent).day
++++dateComponents.hour+=+Calendar.current.dateComponents([.hour],+from:+previous,+to:+recent).hour
++++dateComponents.minute+=+Calendar.current.dateComponents([.minute],+from:+previous,+to:+recent).minute
++++dateComponents.second+=+Calendar.current.dateComponents([.second],+from:+previous,+to:+recent).second
++++return+dateComponents
+++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4599405|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>extension Date {
static func - (recent: Date, previous: Date) -&gt; DateComponents {
 var dateComponents = DateComponents()
 dateComponents.year = Calendar.current.dateComponents([.day], from: previous, to: recent).year
 dateComponents.month = Calendar.current.dateComponents([.month], from: previous, to: recent).month
 dateComponents.day = Calendar.current.dateComponents([.day], from: previous, to: recent).day
 dateComponents.hour = Calendar.current.dateComponents([.hour], from: previous, to: recent).hour
 dateComponents.minute = Calendar.current.dateComponents([.minute], from: previous, to: recent).minute
 dateComponents.second = Calendar.current.dateComponents([.second], from: previous, to: recent).second
 return dateComponents
 }
}
</code></pre>

I'm wondering if there is some new and awesome possibility to get the amount of days between two NSDates in Swift / the "new" Cocoa?

E.g. like in Ruby I would do:

<pre><code>(end_date - start_date).to_i
</code></pre>

Swift days between two NSDates

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我想知道在Swift /“新”可可中是否有一些新的和令人惊叹的可能性来获得两个NSDates之间的天数？例如，在Ruby中，我会这样做：(end_date - start_date).to_i

问两个NSDates之间的快捷天数
EN

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问两个NSDates之间的快捷天数EN