A side question on the topic - what would likely to happen if I have a connecting flights via HKG:
1. flight into HKG on my bday, the connecting flight departing passed midnight.
2. flight into HKG on the bday before, hence the connecting flight departing exactly on my bday.

Of course asking this because the connecting flight is a long-haul I'm a SL and needed a mileage run on my bday month.