When flying from Hong Kong to Poznan, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Most people fly into Poznan Lawica (POZ) if they book a flight to Poznan from Hong Kong. Lawica is conveniently located just 7.0 km from Poznan’s city centre.
This is defined as Hong Kong Intl Airport (HKG) and Poznan Lawica Airport (POZ). Codes like Poznan Lawica Airport are often used to just call airports uniquely.