Bicycle Day is an unofficial celebration on April 19 of the psychedelic revolution and the first psychedelic trip on LSD by Albert Hofmann in 1943, in tandem with his bicycle ride home from Sandoz Labs. It is commonly celebrated by ingesting psychedelics and riding a bike, sometimes in a parade, and often with psychedelic-themed festivities. The holiday was first named and declared in 1985 by Thomas Roberts, a psychology professor at Northern Illinois University, but has likely been celebrated by psychedelic enthusiasts since the beginning of the psychedelic era, and celebrated in popular culture since at least 2004.
Bicycle Day, a psychedelic holiday
On April 19, in the year 0, Bicycle Day, a psychedelic holiday. This event is recorded as a Holidays event in the history of April 19, one of 299 recorded events on this date across all of history.
Key Facts
- This event took place on April 19, 0 (AD era).
- It is categorised as a Holidays event in recorded history.
- Referenced in 2 Wikipedia articles.
- Wikipedia source last updated on 14 March 2026.
On This Date in History 299
This article draws on content from Wikipedia, available under CC BY-SA 4.0.
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