The pair face lengthy suspensions after missing drugs tests, one on the eve of the Athens Olympics last summer.
They were set to learn their fate by the end of February but the Greek athletics governing body postponed the decision after late evidence was submitted.
Kenteris, the Sydney Olympics 200 metres winner, and Thanou, runner-up in the 100m in 2000, both face two-year suspensions if found guilty.
The pair have been suspended by the International Association of Athletics Federations (IAAF) for missing tests in Tel Aviv, Chicago and Athens.
They were also issued with an official warning last year by the IAAF after they were found to be training in Qatar rather than Crete as they had told Greek athletics officials.