In 1994, the Hellenic Parliament passed Law 2193/1994 which designated May 19 as a "day of remembrance for the genocide of the Greeks of Pontus."
It's worth noting that in 1998 the Hellenic Parliament passed Law 2645/1998 which inaugurated September 14 as a day of national mourning for the genocide of all Greeks throughout the entire region of Asia Minor (including Pontus) which in effect was an amendment to the 1994 decision.
Source - Greece's Official Repository of Legislature