一天的开始/一天的结束 - 斯威夫特4

Question

    -(NSDate *)beginningOfDay:(NSDate *)date
{
    NSCalendar *cal = [NSCalendar currentCalendar];
    NSDateComponents *components = [cal components:( NSMonthCalendarUnit | NSYearCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate:date];

    [components setHour:0];
    [components setMinute:0];
    [components setSecond:0];

    return [cal dateFromComponents:components];

}

-(NSDate *)endOfDay:(NSDate *)date
{
    NSCalendar *cal = [NSCalendar currentCalendar];
    NSDateComponents *components = [cal components:(  NSMonthCalendarUnit | NSYearCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate:date];

    [components setHour:23];
    [components setMinute:59];
    [components setSecond:59];

    return [cal dateFromComponents:components];

}

当我打电话：[self endOfDay：[NSDate date]]; 我得到了本月的第一天......为什么？我使用这两种方法，因为我需要一个从第一个日期的第一秒开始的间隔（beginningOfDay：date1）到第二个日期的最后一秒（endOfDay：Date2）......

Answer 1

一天的开始/一天的结束 - 斯威夫特4

  // Extension

extension Date {
    var startOfDay: Date {
        return Calendar.current.startOfDay(for: self)
    }

    var endOfDay: Date {
        var components = DateComponents()
        components.day = 1
        components.second = -1
        return Calendar.current.date(byAdding: components, to: startOfDay)!
    }

    var startOfMonth: Date {
        let components = Calendar.current.dateComponents([.year, .month], from: startOfDay)
        return Calendar.current.date(from: components)!
    }

    var endOfMonth: Date {
        var components = DateComponents()
        components.month = 1
        components.second = -1
        return Calendar.current.date(byAdding: components, to: startOfMonth)!
    }
}

// End of day = Start of tomorrow minus 1 second
// End of month = Start of next month minus 1 second

Answer 2

您在

中缺少NSDayCalendarUnit

NSDateComponents *components = [cal components:( NSMonthCalendarUnit | NSYearCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate:date];

Answer 3

在iOS 8+中，这非常方便;你可以这样做：

let startOfDay = NSCalendar.currentCalendar().startOfDayForDate(date)

要结束一天的结束，那么只需使用NSCalendar方法23小时59分59秒，具体取决于您如何定义结束日期。

// Swift 2.0
let components = NSDateComponents()
components.hour = 23
components.minute = 59
components.second = 59
let endOfDay = NSCalendar.currentCalendar().dateByAddingComponents(components, toDate: startOfDay, options: NSCalendarOptions(rawValue: 0))

Date Math

Apple iOS NSCalendar Documentation。（参见章节：日历计算）

NSCalendar methods discussed by NSHipster

Answer 4

Swift 4 简单而精确的答案。

开始时间：00：00：00

结束时间：23：59：59.5

let date = Date() // current date or replace with a specific date
let calendar = Calendar.current
let startTime = calendar.startOfDay(for: date)
let endTime = calendar.date(bySettingHour: 23, minute: 59, second: 59, of: date)

Answer 5

我对NSDate的Swift扩展：

Swift 1.2

extension NSDate {

    func beginningOfDay() -> NSDate {
        var calendar = NSCalendar.currentCalendar()
        var components = calendar.components(.CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay, fromDate: self)
        return calendar.dateFromComponents(components)!
    }

    func endOfDay() -> NSDate {
        var components = NSDateComponents()
        components.day = 1
        var date = NSCalendar.currentCalendar().dateByAddingComponents(components, toDate: self.beginningOfDay(), options: .allZeros)!
        date = date.dateByAddingTimeInterval(-1)!
        return date
    }
}

Swift 2.0

extension NSDate {

    func beginningOfDay() -> NSDate {
        let calendar = NSCalendar.currentCalendar()
        let components = calendar.components([.Year, .Month, .Day], fromDate: self)
        return calendar.dateFromComponents(components)!
    }

    func endOfDay() -> NSDate {
        let components = NSDateComponents()
        components.day = 1
        var date = NSCalendar.currentCalendar().dateByAddingComponents(components, toDate: self.beginningOfDay(), options: [])!
        date = date.dateByAddingTimeInterval(-1)
        return date
    }
}

Answer 6

Swift 4.2 - XCode 10 Date级而不是NSDate和Calender而不是NSCalender

extension Date {

    var startOfDay : Date {
        let calendar = Calendar.current
        let unitFlags = Set<Calendar.Component>([.year, .month, .day])
        let components = calendar.dateComponents(unitFlags, from: self)
        return calendar.date(from: components)!
   }

    var endOfDay : Date {
        var components = DateComponents()
        components.day = 1
        let date = Calendar.current.date(byAdding: components, to: self.startOfDay)
        return (date?.addingTimeInterval(-1))!
    }
}

用法：

    let myDate = Date()
    let startOfDate = myDate.startOfDay
    let endOfDate = myDate.endOfDay

Answer 7

我认为在Swift中最简洁的方法如下：

extension Date {
    func startOfDay() -> Date {
        return Calendar.current.startOfDay(for: self)
    }
    func endOfDay() -> Date {
        return Calendar.current.date(bySettingHour: 23, minute: 59, second: 59, of: self) ?? self
    }
}

Answer 8

您不必将组件设置为零，只需忽略它们：

-(NSDate *)beginningOfDay:(NSDate *)date
{
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:date];
    return [calendar dateFromComponents:components];
}

Answer 9

Swift 3

main.js

Answer 10

Swift3 使用 * XCode8
Apple正在从类名中删除NS，以便NSDate可以换出Date。如果你试图让他们说他们总是会失败，你可能会得到一个编译器警告，但是当你在操场上运行时它们可以正常工作。

我将核心数据模型中生成的NSDate替换为Date，但它们仍可用。

extension Date {
  func startTime() -> Date {
    return Calendar.current.startOfDay(for: self)
  }

  func endTime() -> Date {
    var components = DateComponents()
    components.day = 1
    components.second = -1
    return Calendar.current.date(byAdding: components, to: startTime())!
  }
}

Answer 11

对我来说，这里没有任何答案，否则stackoverflow工作的地方。为了开始今天，我做到了这一点。

NSCalendar * gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian]; 
[gregorian setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];    
NSDateComponents *components = [gregorian components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay fromDate:[NSDate date]]; 
[components setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]]; 
NSDate *beginningOfToday = [gregorian dateFromComponents:components];

请注意[gregorian setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];和[components setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];。

创建日历时，它会使用当前时区进行初始化，并且从其组件中提取日期时，由于NSDate没有时区，因此将当前时区的日期视为UTC时区。因此，我们需要在提取组件之前设置时区，然后在从这些组件中提取日期时设置时区。

Answer 12

您在组件中缺少NSDayCalendarUnit。

Answer 13

获得结果的另一种方法：

NSDate *date = [NSDate date];

NSDateComponents *components = [[NSDateComponents alloc] init];
components.day = [[NSCalendar currentCalendar] ordinalityOfUnit:(NSCalendarUnitDay) inUnit:(NSCalendarUnitEra) forDate:date];
NSDate *dayBegin = [[NSCalendar currentCalendar] dateFromComponents:components];

components.day += 1;
NSDate *dayEnd = [[NSCalendar currentCalendar] dateFromComponents:components];

Answer 14

由于iOS 8.0+ / macOS 10.12+ / tvOS 10.0+ / watchOS 3.0+基金会内置了一个内置功能，您可以直接使用它。无需实现自己的功能。

public func startOfDay(for date: Date) -> Date

所以你可以这样使用它：

let midnightDate = Calendar(identifier: .gregorian).startOfDay(for: Date())

值得记住的是，这需要考虑设备时区。如果您想拥有例如UTC区域，可以在.timeZone上设置calendar。

链接到Apple参考页面：https://developer.apple.com/reference/foundation/nscalendar/1417161-startofday。

Answer 15

使用dateInterval(of:start:interval:for:)

的Calendar的另一种方式

返回时startDate包含当天的开始时间，interval包含当天的秒数。

func startAndEnd(of date : Date) -> (start : Date, end : Date) {
    var startDate = Date()
    var interval : TimeInterval = 0.0
    Calendar.current.dateInterval(of: .day, start: &startDate, interval: &interval, for: date)
    var endDate = startDate.addingTimeInterval(interval-1)
    return (start : startDate, end : endDate)
}

let (start, end) = startAndEnd(of: Date())
print(start, end)

Answer 16

快速4

    var calendar = Calendar.current
    calendar.timeZone = NSTimeZone(abbreviation: "UTC")! as TimeZone
    let dateAtMidnight = calendar.startOfDay(for: Date())

    //For End Date
    var components = DateComponents()
    components.day = 1
    components.second = -1

    let dateAtEnd = calendar.date(byAdding: components, to: dateAtMidnight)

    print("dateAtMidnight :: \(dateAtMidnight)")
    print("dateAtEnd :: \(dateAtEnd!)")

Answer 17

这是我在Swift 4.2中使用的：

    let calendar = Calendar.current
    let fromDate = calendar.startOfDay(for: Date())
    let endDate = calendar.date(bySettingHour: 23, minute: 59, second: 59, of: Date())

对我来说就像是一种魅力。您可以将此扩展名添加到Date的开始日期和结束日期的扩展名中，但是请记住，添加扩展名会增加编译时间（除非与该类位于同一文件中），因此，如果仅在一个位置需要它或在一堂课中...不要使用扩展名。

Answer 18

extension Date {
    func stringFrom(dateFormat: String) -> String {
        let formatter = DateFormatter()
        formatter.dateFormat = dateFormat
        return formatter.string(from: self)
    }

    func firstSecondInDay() -> Date {
        let dayStr = self.stringFrom(dateFormat: "yyyy-MM-dd")
        let firstSecondStr = "\(dayStr) 00:00:00"
        let format = DateFormatter()
        format.dateFormat = "yyyy-MM-dd HH:mm:ss"
        return format.date(from: firstSecondStr)!
    }

    func lastSecondInDay() -> Date {
        let dayStr = self.stringFrom(dateFormat: "yyyy-MM-dd")
        let laseSecondStr = "\(dayStr) 23:59:59"
        let format = DateFormatter()
        format.dateFormat = "yyyy-MM-dd HH:mm:ss"
        return format.date(from: laseSecondStr)!
    }
}

Answer 19

仅供参考，在Swift 4中设置一天的开始和结束的简单方法，

var comp: DateComponents = Calendar.current.dateComponents([.year, .month, .day, .hour, .minute, .second], from: Date())
comp.hour = 0
comp.minute = 0
comp.second = 0
comp.timeZone = TimeZone(abbreviation: "UTC")!


//Set Start of Day
let startDate : Date = Calendar.current.date(from: comp)!
print(“Day of Start : \(startDate)")


//Set End of Day
comp.hour = 23
comp.minute = 59
comp.second = 59

let endDate : Date = Calendar.current.date(from:comp)!
print("Day of End : \(endDate)")

Answer 20

日历单位应视为间隔。从iOS 10开始，Calendar为此提供了一些不错的方法

let day = Calendar.autoupdatingCurrent.dateInterval(of: .day, for: Date())
day?.end
day?.start

您可以使用相同的方法来获取任何日历组件的开始/结束（周/月/年等）

Answer 21

在Swift 3及更高版本中

extension Date {
    var startOfDayDate: Date {
        return Calendar.current.startOfDay(for: self)
    }

    var endOfDayDate: Date {
        let nextDayDate = Calendar.current.date(byAdding: .day, value: 1, to: self.startOfDayDate)!
        return nextDayDate.addingTimeInterval(-1)
    }
}

用法：

var currentDayStart = Date().startOfDayDate
var currentDayEnd = Date().endOfDayDate

Answer 22

在Swift 5.3中，Calendar.current.startOfDay（）和Calendar.current.date（bySettingHour :, minutes :, second :, of :)都是时区特定的。如果您希望将日期归一化为相同的时间（而不考虑时区），则应使用这样的GMT时间。

// Normalize time of aDate to 12:00 GMT
let aDate = Date()
let twelveGMT = 12 + TimeZone.current.secondsFromGMT() / 3600
let normalizedDate = Calendar.current.date(bySettingHour: twelveGMT, minute: 0, second: 0, of: aDate)

Answer 23

由于 Calendar 结构包含 startOfDay(for:)，我发现最好将 endOfDay(for:) 方法封装在 Calendar 上的扩展中，而不是在 Date 中。< /p>

以下代码可以放在 Playground 文件中以便快速执行。

import Foundation

extension Calendar {

    func endOfDay(for date: Date) -> Date {

        // Get the start of the date argument.
        let dayStart = self.startOfDay(for: date)

        // Add one day to the start of the day 
        // in order to get the start of the following day.            
        guard let nextDayStart = self.date(byAdding: .day, value: 1, to: dayStart) else {
            preconditionFailure("Expected start of next day")
        }

        // Create date components that will subtract a single
        // second from the start of the next day. This will
        // allow you to get the last hour, last minute, and last
        // second of the previous day, which is the day for the 
        // date argument that was passed to this method.
        var components = DateComponents()
        components.second = -1

        // Add the date components to the date for the next 
        // day, which will perform the subtraction of the single
        // second. This will return the end of the day for the date
        // that was passed into this method.
        guard let dayEnd = self.date(byAdding: components, to: nextDayStart) else {
            preconditionFailure("Expected end of day")
        }

        // Simply return the date value.
        return dayEnd
    }

}

要查看格式化的日期，请创建一个 DateFormatter 并打印输出。

let formatter = DateFormatter()
formatter.dateStyle = .long
formatter.timeStyle = .long
Calendar.current.endOfDay(for: Date()) // "Dec 31, 2020 at 11:59 PM"

NSDate从一天开始到一天结束

23 个答案:

一天的开始/一天的结束 - 斯威夫特4