iOS时间戳与日历大全

1,是否为今天

    NSCalendar *calendar = [NSCalendar currentCalendar];
    int unit = NSCalendarUnitDay | NSCalendarUnitMonth |  NSCalendarUnitYear;
    // 1.获得当前时间的年月日
    NSDateComponents *nowCmps = [calendar components:unit fromDate:[NSDate date]];
    // 2.获得self的年月日
    NSDateComponents *selfCmps = [calendar components:unit fromDate:self];
    return
    (selfCmps.year == nowCmps.year) &&
    (selfCmps.month == nowCmps.month) &&
    (selfCmps.day == nowCmps.day);

2,是否为昨天

    // 2014-05-01
    NSDate *nowDate = [[NSDate date] dateWithYMD];
    // 2014-04-30
    NSDate *selfDate = [self dateWithYMD];
    // 获得nowDate和selfDate的差距
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *cmps = [calendar components:NSCalendarUnitDay fromDate:selfDate toDate:nowDate options:0];
    return cmps.day == 1;

3,是否为前天

    // 2014-05-01
    NSDate *nowDate = [[NSDate date] dateWithYMD];
    
    // 2014-04-30
    NSDate *selfDate = [self dateWithYMD];
    
    // 获得nowDate和selfDate的差距
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *cmps = [calendar components:NSCalendarUnitDay fromDate:selfDate toDate:nowDate options:0];
    return cmps.day == 2;

- (NSDate *)dateWithYMD
{
    NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
    fmt.dateFormat = @"yyyy-MM-dd";
    NSString *selfStr = [fmt stringFromDate:self];
    return [fmt dateFromString:selfStr];
}

一次不写多了,上次写了很多,居然没有保存,烦死了~~~~!!!