NSDate从一天开始到一天结束

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

开始日/结束日 - 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

你错过NSDayCalendarUnit了

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

Answer 3

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 4

在iOS 8+中,这非常方便; 你可以做:

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

为了结束一天的结束,只需使用NSCalendar方法23小时59分59秒,具体取决于您如何定义一天结束.

// 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))

日期数学

Apple iOS NSCalendar文档.(参见章节:日历计算)

NSHipster讨论了NSCalendar方法.

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与Date类而不是NSDate而Calender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

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 9

对我来说，这里和 stackoverflow 上其他地方的答案都不起作用。为了今天开始，我这样做了。

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];

注意这个[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，并且当从其组件中提取日期时，由于 NSDate 没有时区，因此当前时区的日期被视为 UTC 时区。因此，我们需要在提取组件之前以及稍后从这些组件中提取日期时设置时区。