When flying from Asheville to Latrobe, Pennsylvania, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Asheville Regional Airport to Latrobe Westmoreland County Airport flight would often be abbreviated as a AVL to LBE flight.