Am I planning my RT-PCR test timing correctly for my flight from the U.S. to Bangkok?

The traveler is inquiring about the timing of their RT-PCR COVID-19 test before a flight to Bangkok from the U.S. They have scheduled the test for January 12th at 4:30 PM, with a departure flight on January 15th at 6:50 AM, including a layover in Korea. Respondents confirm that the test timing seems appropriate, and suggest obtaining a fit to fly certificate along with ensuring the results contain the necessary information.