にゃんにゃんにゃんの日 2月22日 猫の日 ネコの日 ねこの日 ねこのひ
February 22, or 2.22
Read "Ni Ni Ni", then taken further into the day pun "nyan nyan nyan," artists have taken this and made February 22 into the day of catgirl omake.