How I can set a date string from twitter to a NSDATE - iphone

Question

The date you get back from twitter is in this format Fri Aug 07 12:40:04 +0000 2009. I am able to assign the value to a NSDate without issue. However, when I attempt to use NSDateFormatter, I get a nil returned to me. What am I missing?
NSDate *createdAt = [messageData objectForKey:#"created_at"];
NSDateFormatter *format = [[NSDateFormatter alloc] init];
[format setDateFormat:#"M/d/yy HH:mm"];
NSString *dateString = [format stringFromDate:createdAt];
label.text = dateString;

Answer 1

i had the same question, and i could not resolve it with the current above answers. so here is what worked for me:
NSDateFormatter *df = [[[NSDateFormatter alloc] init] autorelease];
//Wed Dec 01 17:08:03 +0000 2010
[df setDateFormat:#"eee, dd MMM yyyy HH:mm:ss ZZZZ"];
NSDate *date = [df dateFromString:[[tweets objectAtIndex: storyIndex] objectForKey: TWITTER_CREATED_AT_JSON_KEY]];
[df setDateFormat:#"eee MMM dd yyyy"];
NSString *dateStr = [df stringFromDate:date];
where tweets is an NSMutableArray filled with NSDictionary objects, storyIndex being the row int value (in the tableview), and TWITTER_CREATED_AT_JSON_KEY being a constant NSString with value created_at. use the dateStr wherever you wish to display the date

Answer 2

If the object associated with the #"created_at" key is a valid NSDate object, this code should work.
However, I'm guessing that it is actually an NSString. If so, it will produce the behavior you're describing.
If I'm right, the code snippet above is assigning an NSString object to an NSDate reference. NSDictionary returns untyped 'id' objects, so the compiler won't give you a type mismatch warning.
You'll have to use NSDateFormatter to parse the string into an NSDate (see dateFromString:).

Answer 3

It looks likes, Twitter changes the format again and again. These works for me now. Don't forget to set the locale.
NSDateFormatter *df = [[[NSDateFormatter alloc] init] autorelease];
//Mon, 29 Oct 2012 12:24:50 +0000
[df setDateFormat:#"EEE, dd LLL yyyy HH:mm:ss ZZZ"];
[df setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:#"en_US"] autorelease]];
NSDate *date = [df dateFromString:[element valueForKey:#"created_at"]];
[df setDateFormat:#"yyyy-MM-dd HH:mm"];
NSString *dateStr = [df stringFromDate:date];
[element valueForKey:#"created_at"] - date from twitter

Answer 4

Above nothing worked for me - try this for Twitter: (I've also included a nice nsdate category for better showing date
lbl = (UILabel *)[cell viewWithTag:16];
NSDateFormatter *df = [[NSDateFormatter alloc] init];
//"created_at": "Tue Jul 09 07:45:01 +0000 2013",
[df setDateFormat:#"EEE MMM d HH:mm:ss ZZZZ yyyy"];
NSTimeInterval timeIntveral = [[df dateFromString:[[_twitterArray objectAtIndex:indexPath.row] objectForKey:#"created_at"]] timeIntervalSince1970];
NSDate *date = [[NSDate alloc] initWithTimeIntervalSince1970:timeIntveral];
//will work if you added the nsdate category, linked above
NSString *ago = [date timeAgo];
NSLog(#"Output is: \"%#\" %.f", ago,timeIntveral);
lbl.text = ago;
Hope this helps!

Answer 5

First off, what are you using stringFromDate: for? That's if you already have an NSDate and want to make a string representing it.
Moreover, when you do use the date formatter, you're giving it a format string that doesn't match the date string you're trying to interpret.
Change the format string to match your date strings, and use dateFromString: instead of stringFromDate: (with the attendant changes to your variable declarations), and it should work.