Question

I am trying to do a date from string however it always makes the date in the month of January… Why?

Code:

NSMutableArray *dateArray = [NSMutableArray array];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"YYYYMMDD"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];

for (id <NSFetchedResultsSectionInfo> sectionInfo in [fetchedResultsController sections]) {
    NSLog(@"Adding date: %@", [sectionInfo name]);
    NSDate *newDate = [dateFormatter dateFromString:[sectionInfo name]];
    NSLog(@"Adding date 2: %@", newDate);
    [dateArray addObject:newDate];
}

LOGS:

2012-03-01 15:14:48.124 MyApp[21793:fb03] Adding date: 20120827
2012-03-01 15:14:48.124 MyApp[21793:fb03] Adding date 2: 2012-01-27 00:00:00 +0000
2012-03-01 15:14:48.125 MyApp[21793:fb03] Adding date: 20120830
2012-03-01 15:14:48.125 MyApp[21793:fb03] Adding date 2: 2012-01-30 00:00:00 +0000
2012-03-01 15:14:48.125 MyApp[21793:fb03] Adding date: 20120831
2012-03-01 15:14:48.126 MyApp[21793:fb03] Adding date 2: 2012-01-31 00:00:00 +0000
2012-03-01 15:14:48.126 MyApp[21793:fb03] Adding date: 20120906
2012-03-01 15:14:48.127 MyApp[21793:fb03] Adding date 2: 2012-01-06 00:00:00 +0000
2012-03-01 15:14:48.127 MyApp[21793:fb03] Adding date: 20120907
2012-03-01 15:14:48.128 MyApp[21793:fb03] Adding date 2: 2012-01-07 00:00:00 +0000
2012-03-01 15:14:48.128 MyApp[21793:fb03] Adding date: 20120910
2012-03-01 15:14:48.128 MyApp[21793:fb03] Adding date 2: 2012-01-10 00:00:00 +0000
2012-03-01 15:14:48.129 MyApp[21793:fb03] Adding date: 20120913
2012-03-01 15:14:48.129 MyApp[21793:fb03] Adding date 2: 2012-01-13 00:00:00 +0000

Answer 1

The day of month specifier is dd, not DD. Also, you might want to use the yyyy format for years, as YYYY means the ISO ‘Week of Year’, and may be different from the actual year. So your final format should look like:

[dateFormatter setDateFormat:@"yyyyMMdd"];