Tempe, Arizona. Feb 26, 2013 WORLD SPAY DAY @ TEMPE MARKETPLACE. Join the Arizona Humane Society (AHS) for World Spay Day 2013 as we lead the fight in pet overpopulation and raise awareness of Arizona’s extreme pet overpopulation crisis. AHS, along with their mascot, Humane Eddy, will celebrate World Spay Day by handing out 500 free spay and neuter vouchers (while supplies last). Click on link for details.