Return flights and visa conditions

Hello, I have booked my return flights for the end of my teaching contract in June. I have applied for a working Z type but it seems it will be issued as a 30 day or 000 day Z type and then transferred to a residency permit when I get to China. Will I have problems getting through the airport if my return flight extends over how long my visa says even though it is a working Z type and will be a residency permit? Thanks.