Bunny Day is a [[date pun]] that occurs on August 2nd or 21st.

"バニー" (banii) looks similar to the numerals 八二一, which respectively mean 8, 2, and 1. The same pun can also result from goroawase: 8 (ba) + 2 (ni) and 8 (ba) + 2 (ni) + 1 (i).

Some also designate August 23rd as Bunny Day or "Banii-san no Hi" using goroawase: 8 (ba) + 2 (ni) + 1 (i) + 3 (san).
バニーの日