I always time my races and then cross check with the official times.
If there's no oficial one, then why not time it yourself?
Just make sure that you press the start button just before crossing the line (if you're looking ahead, just as your eyes lose contact with it) and then again, when you have fully crossed the finish.
It won't be 100% accurate but this way you will not take seconds off. You may add 1 or 2 but that's better than nothing
