Convert date in MM/dd/yyyy format

NSString *str = @"2012-10-30"; /// here this is your date with format yyyy-MM-dd

NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease]; // here we create NSDateFormatter object for change the Format of date..
[dateFormatter setDateFormat:@"yyyy-MM-dd"]; //// here set format of date which is in your output date (means above str with format)

NSDate *date = [dateFormatter dateFromString: str]; // here you can fetch date from string with define format

dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setDateFormat:@"dd/MM/yyyy"];// here set format which you want...

NSString *convertedString = [dateFormatter stringFromDate:date]; here convert date in NSString
NSLog(@"Converted String : %@",convertedString);