We just passed one:
Earth Day. A day which was invented by a convicted murderer and whose purpose the Left has further twisted from a look at reasonable, common- sense ways that everyday people can help care for the environment, into an excuse for dirty hippies to howl incoherent excuses for poetry and for eco- hypocrites like Al Gore to give long- winded speeches about how global warming will kill us all unless everyone (Except themselves, of course) buries their car, becomes vegan, and goes back to living like the Flintstones.
And another one is coming up:
May Day, aka Worker's Solidarity Day. It's a day for repulsive, insane, drug- addled Communist and Anarchist scum to engage in what they euphemistically call "A series of autonomous direct actions using a diversity of tactics to promote social justice and raise awareness of the plight of the oppressed workers," but which normal people refer to as vandalism, violence, looting and rioting.