Change NSDateFormatter For Dates in Array? - iphone

Question

Right now my dates look like this:`2011-01-01 5:45:23 +0000
I want them to look like this: 2011-01-01 00:00:00 +0000 (notice how everything is 00 beside the date, month, and year).
I have an array of NSdates which is fetched from this code:
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Session" inManagedObjectContext:self.managedObjectContext];
[request setEntity:entity];
[request setResultType:NSDictionaryResultType];
[request setReturnsDistinctResults:YES]; //set to YES if you only want unique values of the property
[request setPropertiesToFetch :[NSArray arrayWithObject:#"timeStamp"]]; //name(s) of properties you want to fetch
NSError *error;
NSArray *objects = [managedObjectContext executeFetchRequest:request error:&error];
NSArray *data = [objects valueForKey:#"timeStamp"];
NSLog(#"The content of data is%#", data);
I want to remove daylight savings and have 0:00:00 for the time aspect of each date, thus I need this NSDateFormatter method:
NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
[formatter setDateFormat:#"YYYY-MM-dd HH:mm:ss"]; // e.g., set for mysql date strings
[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
NSString* mysqlGMTString = [formatter stringFromDate:[NSDate date]];
So how can I combine the two to work together?

Answer 1

NSDateFormatter *formatter = [[[NSDateFormatter alloc] init];
[formatter setDateFormat:#"YYYY-MM-dd HH:mm:ss"];
[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
for (NSDate *d in data) {
NSString* mysqlGMTString = [formatter stringFromDate:d];
// ...
}
[formatter release];

Answer 2

Since your requirement is to have strings in the data array, this code should suit your purpose.
NSMutableArray * resultsArray = [NSMutableArray array];
NSCalendar * gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
[gregorian setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
NSUInteger flags = ( NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit );
NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
[formatter setDateFormat:#"yyyy-MM-dd HH:mm:ss Z"];
[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
[datesArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSDate * date = [gregorian dateFromComponents:[gregorian components:flags fromDate:obj]];
[resultsArray addObject:[formatter stringFromDate:date]];
}];
resultsArray will contain the strings that you need. Now you can have data referring to the object
As for the search with a date part,
- (void)calendarMonthView:(TKCalendarMonthView *)monthView didSelectDate:(NSDate *)d {
// Assuming `data` is from the code above & the date is in `00:00:00 +0000` form.
NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
[formatter setDateFormat:#"yyyy-MM-dd HH:mm:ss Z"];
[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
NSString * dateString = [formatter stringFromDate:d];
if ( [data containsObject:dateString] ) {
// Push object to detail view??
}
}
Also use yyyy instead of YYYY. They are not the same.