Question

我想做的是今天，昨天，本周，本周，本周，本月，上个月的变量准备好比较要在UITableView的titleForHeaderInSection上添加标题的NSDate

我想要的是在下面的代码中手动完成的日期2009-12-11

 NSDate *today = [NSDate dateWithString:@"2009-12-11 00:00:00 +0000"];
 NSDate *yesterday = [NSDate dateWithString:@"2009-12-10 00:00:00 +0000"];
 NSDate *thisWeek = [NSDate dateWithString:@"2009-12-06 00:00:00 +0000"];
 NSDate *lastWeek = [NSDate dateWithString:@"2009-11-30 00:00:00 +0000"];
 NSDate *thisMonth = [NSDate dateWithString:@"2009-12-01 00:00:00 +0000"];
 NSDate *lastMonth = [NSDate dateWithString:@"2009-11-01 00:00:00 +0000"];

Answer 1

改编自Date and Time Programming Guide：

// Right now, you can remove the seconds into the day if you want
NSDate *today = [NSDate date];

// All intervals taken from Google
NSDate *yesterday = [today dateByAddingTimeInterval: -86400.0];
NSDate *thisWeek  = [today dateByAddingTimeInterval: -604800.0];
NSDate *lastWeek  = [today dateByAddingTimeInterval: -1209600.0];

// To get the correct number of seconds in each month use NSCalendar
NSDate *thisMonth = [today dateByAddingTimeInterval: -2629743.83];
NSDate *lastMonth = [today dateByAddingTimeInterval: -5259487.66];

如果您想要正确的天数，具体取决于月份，则应使用NSCalendar。

Answer 2

可能是一个更好的方式来写这个，但在这里我提出了Ben的NSCalendar建议并从那里工作到NSDateComponents

NSCalendar *cal = [NSCalendar currentCalendar];
NSDateComponents *components = [cal components:( NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond ) fromDate:[[NSDate alloc] init]];

[components setHour:-[components hour]];
[components setMinute:-[components minute]];
[components setSecond:-[components second]];
NSDate *today = [cal dateByAddingComponents:components toDate:[[NSDate alloc] init] options:0]; //This variable should now be pointing at a date object that is the start of today (midnight);

[components setHour:-24];
[components setMinute:0];
[components setSecond:0];
NSDate *yesterday = [cal dateByAddingComponents:components toDate: today options:0];

components = [cal components:NSWeekdayCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:[[NSDate alloc] init]];

[components setDay:([components day] - ([components weekday] - 1))]; 
NSDate *thisWeek  = [cal dateFromComponents:components];

[components setDay:([components day] - 7)];
NSDate *lastWeek  = [cal dateFromComponents:components];

[components setDay:([components day] - ([components day] -1))]; 
NSDate *thisMonth = [cal dateFromComponents:components];

[components setMonth:([components month] - 1)]; 
NSDate *lastMonth = [cal dateFromComponents:components];

NSLog(@"today=%@",today);
NSLog(@"yesterday=%@",yesterday);
NSLog(@"thisWeek=%@",thisWeek);
NSLog(@"lastWeek=%@",lastWeek);
NSLog(@"thisMonth=%@",thisMonth);
NSLog(@"lastMonth=%@",lastMonth);

Answer 3

NSDateComponents今天很高兴：

NSCalendar *cal = [NSCalendar currentCalendar];

NSDate *date = [NSDate date];
NSDateComponents *comps = [cal components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) 
                                                          fromDate:date];
NSDate *today = [cal dateFromComponents:comps];

这会创建一个仅包含年，月和日期的NSDate：

(gdb) po today
2010-06-22 00:00:00 +0200

要获得昨天等，您可以使用NSDateComponents计算它：

NSDateComponents *components = [[NSDateComponents alloc] init];
[components setDay:-1];
NSDate *yesterday = [cal dateByAddingComponents:components toDate:today options:0];

Answer 4

+ (NSDate*)dateFor:(enum DateType)dateType {

    NSCalendar *calendar = [NSCalendar currentCalendar];

    NSDateComponents *comps =
    [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit
                fromDate:[NSDate date]];

    if(dateType == DateYesterday) {

        comps.day--;
    }
    else if(dateType == DateThisWeek) {

        comps.weekday = 1;
    }
    else if(dateType == DateLastWeek) {

        comps.weekday = 1;
        comps.week--;
    }
    else if(dateType == DateThisMonth) {

        comps.day = 1;
    }
    else if(dateType == DateLastMonth) {

        comps.day = 1;
        comps.month--;
    }
    else if(dateType != DateToday)
        return nil;

    return [calendar dateFromComponents:comps];
}

Answer 5

Swift 4.2

let today = Date()
let yesterday = today.addingTimeInterval(-86400.0)
let thisWeek = today.addingTimeInterval(-604800.0)
let lastWeek = today.addingTimeInterval(-1209600.0)

let thisMonth = today.addingTimeInterval(-2629743.83)
let lastMonth = today.addingTimeInterval(-5259487.66)

// components of the date
let calendar = Calendar(identifier: Calendar.Identifier.gregorian)
let components = calendar.dateComponents([.year, .month, .day], from: today)
let (year, month, day) = (components.year, components.month, components.day)

请注意，日期组件是可选的。

Answer 6

其他答案对我不起作用（可能是因为我的时区）。我就是这样做的：

- (BOOL)isOnThisWeek:(NSDate *)dateToCompare
{
    NSCalendar * calendar = [NSCalendar currentCalendar];
    NSDate     * today    = [NSDate date];

    int todaysWeek        = [[calendar components: NSWeekCalendarUnit fromDate:today] week];
    int dateToCompareWeek = [[calendar components: NSWeekCalendarUnit fromDate:dateToCompare] week];

    int todaysYear         = [[calendar components:NSYearCalendarUnit fromDate:today] year];
    int dateToCompareYear  = [[calendar components:NSYearCalendarUnit fromDate:dateToCompare] year];

    if (todaysWeek == dateToCompareWeek && todaysYear == dateToCompareYear) {
        return YES;
    }

    return NO;
}

Answer 7

如果您使用的是iOS 10+或MacOS 10.12+，则可以使用这两种Calendar方法正确执行此操作。

func date(byAdding component: Calendar.Component, value: Int, to date: Date, wrappingComponents: Bool = default) -> Date?（docs）
func dateInterval(of component: Calendar.Component, for date: Date) -> DateInterval?（docs）

以下是Swift 3中如何使用这些方法的示例，以及我所在时区的操场输出。

let calendar = Calendar.current
let now = Date()
// => "Apr 28, 2017, 3:33 PM"

let yesterday = calendar.date(byAdding: .day, value: -1, to: now)
// => "Apr 29, 2017, 3:33 PM"
let yesterdayStartOfDay = calendar.startOfDay(for: yesterday!)
// => ""Apr 29, 2017, 12:00 AM"

let thisWeekInterval = calendar.dateInterval(of: .weekOfYear, for: now)
// => 2017-04-23 04:00:00 +0000 to 2017-04-30 04:00:00 +0000

let thisMonthInterval = calendar.dateInterval(of: .month, for: now)
// => 2017-04-01 04:00:00 +0000 to 2017-05-01 04:00:00 +0000

let aDateInLastWeek = calendar.date(byAdding: .weekOfYear, value: -1, to: now)
let lastWeekInterval = calendar.dateInterval(of: .weekOfYear, for: aDateInLastWeek!)
// => 2017-04-16 04:00:00 +0000 to 2017-04-23 04:00:00 +0000

let aDateInLastMonth = calendar.date(byAdding: .month, value: -1, to: now)
let lastMonthInterval = calendar.dateInterval(of: .weekOfYear, for: aDateInLastMonth!)
// => 2017-03-26 04:00:00 +0000 to 2017-04-02 04:00:00 +0000

奖励：您可以使用DateInterval来测试日期是否在该范围内。从上面继续：

thisWeekInterval!.contains(now)
// => true
lastMonthInterval!.contains(now)
// => false

Answer 8

NSDate *today = [NSDate date]; // Today's date
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *weekdayComponents =[gregorian componentsNSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:today];
NSInteger day = [weekdayComponents day];

Answer 9

我非常喜欢这个项目中包含的THCalendarInfo对象：

http://github.com/jaredholdcroft/kcalendar

我找不到原版。使用此对象，您可以移动到前一天，一周的开始，一个月的开始，一周的一天，一个月的某天......等等。

Answer 10

NSDate *today = [[NSDate alloc] initWithTimeIntervalSinceNow:0];

Answer 11

这是为了检查日期是否是本月

func isOnThisMonth(dateToCompare: NSDate) -> Bool {
    let calendar: NSCalendar = NSCalendar.currentCalendar()
    let today: NSDate = NSDate()
    let todaysWeek: Int = calendar.components(NSCalendarUnit.Month, fromDate: today).month
    let dateToCompareWeek: Int = calendar.components(.Month, fromDate: dateToCompare).month
    let todaysYear: Int = calendar.components(NSCalendarUnit.Year, fromDate: today).year
    let dateToCompareYear: Int = calendar.components(NSCalendarUnit.Year, fromDate: dateToCompare).year
    if todaysWeek == dateToCompareWeek && todaysYear == dateToCompareYear {
        return true
    }
    return false
}

第二个只改变了像这样的弱者的calendarUnit类型

func isOnThisWeek(dateToCompare: NSDate) -> Bool {
    let calendar: NSCalendar = NSCalendar.currentCalendar()
    let today: NSDate = NSDate()
    let todaysWeek: Int = calendar.components(NSCalendarUnit.Weekday, fromDate: today).weekday
    let dateToCompareWeek: Int = calendar.components(.Weekday, fromDate: dateToCompare).weekday
    let todaysYear: Int = calendar.components(NSCalendarUnit.Year, fromDate: today).year
    let dateToCompareYear: Int = calendar.components(NSCalendarUnit.Year, fromDate: dateToCompare).year
    if todaysWeek == dateToCompareWeek && todaysYear == dateToCompareYear {
        return true
    }
    return false
}

我希望这对某人有帮助谢谢。

Answer 12

我回答了类似的问题already，这就是为什么我的回答更好：

Swift 3 ！
利用DateFormatter＆＃34;＆＃34;昨天＆＃34;和＆＃34;今天＆＃34;。这已经由Apple翻译，可以为您节省工作！
使用DateComponentsFormatter已翻译＆＃34; 1周＆＃34;串。（再次为你工作，Apple的礼貌。）你所要做的就是翻译＆＃34;％@ ago＆＃34;串。
其他答案错误地计算了当天从＆＃34;今天＆＃34;昨天＆＃34;昨天＆＃34;固定常数是一个很大的NO-NO，因为reasons。此外，其他答案使用当前日期/时间，他们应该使用结束当天日期/时间。
使用autoupdatingCurrent for Calendar＆amp;区域设置可确保您的应用在Settings.app中立即与用户的日历和语言首选项保持同步。

今天，昨天，本周，上周，本月，上个月......变量获得NSDate

12 个答案: