It seems to me that might should be on another day besides Hitler's birthday.
Here's the reasoning.
420 (cannabis culture)
4:20 or 4/20 (pronounced four-twenty) is a term used in North America as a discreet way to refer to cannabis and, by extension, a way to identify oneself with cannabis culture. Phrases such as "420 friendly" sometimes appear in roommate advertisements, indicating that the current occupants are tolerant of cannabis users.
Origins and Observances
It is widely accepted that in the early 1970s, a group of teenagers at San Rafael High School in San Rafael, California used to meet every day after school at 4:20 p.m. to smoke marijuana at the Louis Pasteur statue.  Many cannabis users continue to observe 4:20 as a time to smoke communally. By extension April 20 ("4/20" in U.S. dating shorthand) has evolved into a counterculture holiday, where people gather to celebrate and consume cannabis.  
The widespread popularity of 4/20 celebrations in the U.S. has brought about calls advocating for the reform of American marijuana laws. The 420 Campaign urges individuals to become involved in the political process and the drug policy reform movement. Specifically, the Campaign calls for leveraging "April 20th as a focal point every year to concentrate pressure on Congress to legalize marijuana." In addition to contacting state and national legislators, people can take action by supporting organizations—such as NORML and MPP—that represent the interests of marijuana users and other concerned citizens.