-(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）......
你错过了NSDayCalendarUnit
NSDateComponents *components = [cal components:( NSMonthCalendarUnit | NSYearCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate:date];
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，并且从其组件中提取日期时，由于NSDate没有时区，因此从当前时区开始的日期将被视为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。
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];
您在组件中缺少NSDayCalendarUnit。
Objective-C的
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDate * startDate = [calendar startOfDayForDate:[NSDate date]];
NSLog(@"start date is %@", startDate);
由于iOS 8.0+ / macOS 10.12+ / tvOS 10.0+ / watchOS 3.0+在基金会有一个内置功能，你可以开箱即用。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。如果你想拥有例如UTC区域，你可以在.timeZone上设置calendar。
链接到Apple参考页面：https://developer.apple.com/reference/foundation/nscalendar/1417161-startofday。
只是使用dateInterval(of:start:interval:for:)的Calendar的另一种方式
返回时，startDate包含当天的开始，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)
对于迅捷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!)")
这是我用于Swift 4.2的内容：
let calendar = Calendar.current
let fromDate = calendar.startOfDay(for: Date())
let endDate = calendar.date(bySettingHour: 23, minute: 59, second: 59, of: Date())
对我来说就像一个魅力。您可以将此添加到Date的开始日期和结束日期的扩展名中，但请记住，添加扩展名会增加编译时间（除非在与该类相同的文件中），因此如果您只需要在一个地方或一个类中...不要使用扩展名。
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)!
}
}
仅供参考，在Swift 4中设置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)")
// 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
日历单位应被视为间隔。从iOS 10开始，Calendar有一些不错的方法
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）
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)
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的结束时间。
// 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))
Apple iOS NSCalendar Documentation。 （参见章节：日历计算）
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
}
}
Swift 4.2 - XCode 10与Date类而不是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
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];
}
斯威夫特3
class func today() -> NSDate {
return NSDate()
}
class func dayStart() -> NSDate {
return NSCalendar.current.startOfDay(for: NSDate() as Date) as NSDate
}
class func dayEnd() -> NSDate {
let components = NSDateComponents()
components.day = 1
components.second = -1
return NSCalendar.current.date(byAdding: components as DateComponents, to: self.dayStart() as Date)
}
Swift3使用* XCode8
Apple正在从类名中删除NS，以便NSDate可以换成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它们时它们工作正常。
我用NSDate替换了核心数据模型中生成的Date，它们仍然有效。
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())!
}
}