When flying from Orlando to Botswana, 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 Orlando Airport to Gaborone Sir Seretse Khama Airport flight would often be abbreviated as a MCO to GBE flight. Maun Airport (MUB), Kasane Airport (BBK), Francistown Airport (FRW) are some additional IATA codes for airports related to your trip.