Baby Blues by Rick Kirkman and Jerry Scott for June 13, 1997
Transcript:
Yesterday was 1 June, Zoe. Can you say June? Jooon. June rhymes with moon. And spoon, and balloon! That's fun to say, isn't it? June... Moon... Spoon... Balloon... Baboon... Loon... Cartoon... Spittoon... Just how many Mister Rogers shows has Mommy been watching?
This strip was in the same position on the original BB site, so my guess is this was a publishing error dating back to when Rick and Jerry submitted these comics in 1997. But yeah, June doesn’t start on the 12th.