NSString *dateString = [NSDateFormatter localizedStringFromDate:[NSDate date] 
                                                      dateStyle:NSDateFormatterShortStyle 
                                                      timeStyle:NSDateFormatterFullStyle];
NSLog(@"%@",dateString);

NSDateFormatter *dateFormatter = [NSDateFormatter alloc];
[dateFormatter setDateFormat:@"yyyy-mm-dd"];

NSString *stringFromDate = [dateFormatter stringFromDate:myNSDate];

[formatter release];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-mm-dd"];

NSString *stringFromDate = [dateFormatter stringFromDate:myNSDate];

[formatter release];

convert nsdate to nsstring format

NSDate to NSString

Objective C