#import <Foundation/Foundation.h>

@interface NSDateFormatterLogger : NSDateFormatter

@end

@implementation NSDateFormatterLogger

- (BOOL)getObjectValue:(__autoreleasing id *)obj forString:(NSString *)string range:(NSRange *)rangep error:(NSError *__autoreleasing *)error
{
    NSLog(@"%@ called", NSStringFromSelector(_cmd));
    return [super getObjectValue:obj forString:string range:rangep error:error];
}

@end

int main(int argc, const char * argv[])
{

    @autoreleasepool {

        NSString * dateString = @"2012-08-16T16:20:52.619000+00:00";

        NSDateFormatterLogger *df = [NSDateFormatterLogger new];
        [df setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ"];
        NSLog(@"%@", [df dateFromString:dateString]);

    }
    return 0;
}