CAAT had initially prohibited all aircraft from entering Thailand for three days, from April 4 to 6.
The move is to stem the Covid-19 contagion.
The order, signed by CAAT director-general Chula Sukamanop, exempts state or military aircraft from landing, emergency landings, technical landings without any passengers disembarking, humanitarian aid and medical or relief flights, repatriation flights and cargo aircraft.
Passengers en route to Thailand prior to this announcement will be subject to a 14-day quarantine in Thailand.