比较NSDate + Period

Question

我有开始日期和持续时间（期间）。例如startDate = '2014-02-12' period = 2。我希望日期2014-02-12，2014-02-14，2014-02-16，....我需要确定当前日期是否已标记。

Answer 1

您可以使用

获得所需的日期

- (id)dateByAddingTimeInterval:(NSTimeInterval)seconds

seconds = period*3600*24

Answer 2

检查开始日期和当前日期之间的差异是否为偶数 天数，请使用NSDateComponents：

NSDate *startDate = ...;
NSDate *currentDate = [NSDate date];
NSCalendar *cal = [NSCalendar currentCalendar];
NSDateComponents *diff = [cal components:NSDayCalendarUnit fromDate:startDate
                                  toDate:currentDate options:0];
NSInteger days = diff.day;
if (days % 2 == 0) {
    // even number of days between start date and current date
}

Answer 3

计算从startDate到givenData的天数，检查结果是否可以被句点整除。

+ (NSInteger)daysWithinEraFromDate:(NSDate *)startDate toDate:(NSDate *)endDate {
    NSCalendar *gregorian = [[NSCalendar alloc]
                             initWithCalendarIdentifier:NSGregorianCalendar];
    [gregorian setTimeZone:[NSTimeZone localTimeZone]];
    // for timezone issue
    NSDate *newDate1 = [startDate dateByAddingTimeInterval:[[NSTimeZone localTimeZone] secondsFromGMT]];
    NSDate *newDate2 = [endDate dateByAddingTimeInterval:[[NSTimeZone localTimeZone] secondsFromGMT]];
    NSInteger startDay = [gregorian ordinalityOfUnit:NSDayCalendarUnit
                                            inUnit: NSEraCalendarUnit forDate:newDate1];
    NSInteger endDay = [gregorian ordinalityOfUnit:NSDayCalendarUnit
                                          inUnit: NSEraCalendarUnit forDate:newDate2];
    return endDay - startDay;
}