the 6th of May - a special holiday, devoted to nursing hangovers and otherwise dealing with the consequences of Cinco de Mayo
Tom: "Hey Dave, why didn't you show up for work yesterday?"
Dave: "It was May 6th, remember?"
Tom: "Duuude, you were so wasted on Cinco de Mayo- you downed like a full bottle of tequila! That must've been a killer hangover!"
Dave: "That's what why we have Seis de Mayo and aspirin."