When flying from Bali to Zimbabwe, 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 Denpasar Bali Ngurah Rai Airport to Harare Airport flight would often be abbreviated as a DPS to HRE flight. Victoria Falls Airport (VFA), Bulawayo Airport (BUQ), Kariba Airport (KAB) are other airports near this flight route and their unique identifiers/IATA codes.