Mexican Independence Day is actually in September. Cinco de Mayo is a made up gringo holiday.
What ever it is they can go celebrate it in Mexico.
cinco de mayo was the date of the Mexicans defeating the French. Not considered a big deal in Mexico. But played up in the US to make Mexicans feel important. I must confess as a lover of latin women (amongst others) and mexican food I have enjoyed many Cinco De Mayo’s. But those days are behind me, sigh.
It's the Mexican Kwanzaa much beloved by liberal schoolteachers
Cinco de Mayo = Karl Marx’s birthday, May 5th.
Earth Day is Vladimir Lenin’s birthday celebration.
If I remember correctly, 17 Sep (El Grito) is the true Mexican Indepenence Day).