Bajoran colonel serving under General Krim who killed Li Nalas while trying to assassinate Sisko during the Circle's coup.
Day Kannu is a Bajoran militia colonel and General Krim's second-in-command in The Siege. During the occupation of Deep Space Nine by Circle-backed forces, Sisko traps Day and his men in a holosuite and releases him to tell Krim that the Cardassians are behind the coup, but Day instead claims the Federation is trying to seize the station.
After Krim learns the truth and returns command to Sisko, Day tries to shoot Sisko in revenge. Li Nalas steps into the blast and is killed, and Day is arrested.