你可以使用NSDate的方法- (id)dateByAddingTimeInterval:(NSTimeInterval)秒，其中秒为60 * 60 * 24 = 86400

swift 5更新

let nextDate = fromDate.addingTimeInterval(60*60*24)

你可以使用NSDate的方法- (id)dateByAddingTimeInterval:(NSTimeInterval)秒，其中秒为60 * 60 * 24 = 86400

在Swift 2.1.1和xcode 7.1 OSX 10.10.5中，你可以使用函数添加任意数量的天数

func addDaystoGivenDate(baseDate:NSDate,NumberOfDaysToAdd:Int)->NSDate
{
    let dateComponents = NSDateComponents()
    let CurrentCalendar = NSCalendar.currentCalendar()
    let CalendarOption = NSCalendarOptions()

    dateComponents.day = NumberOfDaysToAdd

    let newDate = CurrentCalendar.dateByAddingComponents(dateComponents, toDate: baseDate, options: CalendarOption)
    return newDate!
}

函数调用，将当前日期增加9天

var newDate = addDaystoGivenDate(NSDate(), NumberOfDaysToAdd: 9)
print(newDate)

函数调用，将当前日期减少80天

newDate = addDaystoGivenDate(NSDate(), NumberOfDaysToAdd: -80)
 print(newDate)

使用下面的函数，并使用days参数来获取日期daysAhead/daysBehind，只需将参数传递为正，表示未来日期，为负，表示之前日期:

+ (NSDate *) getDate:(NSDate *)fromDate daysAhead:(NSUInteger)days
{
    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    dateComponents.day = days;
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *previousDate = [calendar dateByAddingComponents:dateComponents
                                                     toDate:fromDate
                                                    options:0];
    [dateComponents release];
    return previousDate;
}

我也有同样的问题;使用NSDate扩展:

- (id)dateByAddingYears:(NSUInteger)years
                 months:(NSUInteger)months
                   days:(NSUInteger)days
                  hours:(NSUInteger)hours
                minutes:(NSUInteger)minutes
                seconds:(NSUInteger)seconds
{
    NSDateComponents * delta = [[[NSDateComponents alloc] init] autorelease];
    NSCalendar * gregorian = [[[NSCalendar alloc]
                               initWithCalendarIdentifier:NSCalendarIdentifierGregorian] autorelease];

    [delta setYear:years];
    [delta setMonth:months];
    [delta setDay:days];
    [delta setHour:hours];
    [delta setMinute:minutes];
    [delta setSecond:seconds];

    return [gregorian dateByAddingComponents:delta toDate:self options:0];
}