http://d.hatena.ne.jp/mmasashi/20110103/1294041571 の再現(2011年1月1日~2日にかけてのアラーム鳴らなかった問題)

gistfile1.m

- dateTest:(NSString*)original {
    NSLog(@"\n[dateTest]");
    NSLog(@"original is %@", original);
    NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setDateFormat:@"YYYYMMddHHmmss"];

    // NSString -> NSDate
    NSDate *originalDate = [formatter dateFromString:original];
    NSLog(@"originalDate is %@", originalDate);

    // NSDate -> NSString
    NSString *originalReversed = [formatter stringFromDate:originalDate];
    NSLog(@"originalReversed is %@", originalReversed);
}
- dateTest2:(NSString*)original {
    NSLog(@"\n[dateTest2]");
    NSLog(@"original is %@", original);
    NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setDateFormat:@"yyyyMMddHHmmss"];

    // NSString -> NSDate
    NSDate *originalDate = [formatter dateFromString:original];
    NSLog(@"originalDate is %@", originalDate);

    // NSDate -> NSString
    NSString *originalReversed = [formatter stringFromDate:originalDate];
    NSLog(@"originalReversed is %@", originalReversed);
}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    NSString *date = @"20110101123456";
    [self dateTest:date];
    [self dateTest2:date];

    date = @"20110102123456";
    [self dateTest:date];
    [self dateTest2:date];

    date = @"20110103123456";
    [self dateTest:date];
    [self dateTest2:date];
}

gistfile2.txt

2011-01-05 23:20:39.973 HelloNSDateFormatter[3703:207] 
[dateTest]
2011-01-05 23:20:39.974 HelloNSDateFormatter[3703:207] original is 20110101123456
2011-01-05 23:20:39.976 HelloNSDateFormatter[3703:207] originalDate is 2011-01-01 03:34:56 GMT
2011-01-05 23:20:39.977 HelloNSDateFormatter[3703:207] originalReversed is 20100101123456
2011-01-05 23:20:39.977 HelloNSDateFormatter[3703:207] 
[dateTest2]
2011-01-05 23:20:39.977 HelloNSDateFormatter[3703:207] original is 20110101123456
2011-01-05 23:20:39.978 HelloNSDateFormatter[3703:207] originalDate is 2011-01-01 03:34:56 GMT
2011-01-05 23:20:39.979 HelloNSDateFormatter[3703:207] originalReversed is 20110101123456
2011-01-05 23:20:39.979 HelloNSDateFormatter[3703:207] 
[dateTest]
2011-01-05 23:20:39.980 HelloNSDateFormatter[3703:207] original is 20110102123456
2011-01-05 23:20:39.980 HelloNSDateFormatter[3703:207] originalDate is 2011-01-02 03:34:56 GMT
2011-01-05 23:20:39.981 HelloNSDateFormatter[3703:207] originalReversed is 20110102123456
2011-01-05 23:20:39.981 HelloNSDateFormatter[3703:207] 
[dateTest2]
2011-01-05 23:20:39.982 HelloNSDateFormatter[3703:207] original is 20110102123456
2011-01-05 23:20:39.983 HelloNSDateFormatter[3703:207] originalDate is 2011-01-02 03:34:56 GMT
2011-01-05 23:20:39.983 HelloNSDateFormatter[3703:207] originalReversed is 20110102123456
2011-01-05 23:20:39.983 HelloNSDateFormatter[3703:207] 
[dateTest]
2011-01-05 23:20:39.984 HelloNSDateFormatter[3703:207] original is 20110103123456
2011-01-05 23:20:39.985 HelloNSDateFormatter[3703:207] originalDate is 2011-01-03 03:34:56 GMT
2011-01-05 23:20:39.985 HelloNSDateFormatter[3703:207] originalReversed is 20110103123456
2011-01-05 23:20:39.985 HelloNSDateFormatter[3703:207] 
[dateTest2]
2011-01-05 23:20:39.986 HelloNSDateFormatter[3703:207] original is 20110103123456
2011-01-05 23:20:39.987 HelloNSDateFormatter[3703:207] originalDate is 2011-01-03 03:34:56 GMT
2011-01-05 23:20:39.988 HelloNSDateFormatter[3703:207] originalReversed is 20110103123456