It's on May 5th.

I'm having a small get together for Cinco De Mayo. In my efforts to inform people I like about it I have stumbled across an extraordinary piece of information. Evidently, not everyone in Seattle speaks Spanish. Whats more, the majority of people in Seattle don't even speak enough to figure when Cinco De Mayo takes place. So exactly each time I've invited someone I've been asked "When is it?"

The first few fell victim to my reproachful wrath, but eventually I just lost the will to condescend. In Texas it didn't matter that everyone was either Asian, Indian, or White because it was Texas and so reasonable to expect you to know "Cinco" and "Mayo". Now I am lost in a sea of people who find themselves perfectly comfortable in their inability to speak Spanish.

To be fair, Australia is pretty well removed from Spanish speaking cultures (though I believe Spanish exists in the Phillipines).