The price of a single dogecoin jumped as much as 20% on Tuesday to 42 cents, nearing Friday's all-time high of 45 cents, according to CoinDesk data. On Twitter and Reddit, crypto enthusiasts posted memes featuring the Dogecoin logo, a Shiba Indu dog, with the hashtag #DogeDay and #Doge420.
Social media users also drew links between Doge Day and Weed Day, which is celebrated on April 20 by marijuana smokers.
Dogecoin's popularity has soared this year, buoyed in part by the adoption of bitcoin and other cryptocurrencies by business and mainstream investors.
Last week, the price of a single dogecoin doubled after Tesla CEO Elon Musk, its most prominent supporter and erstwhile public weed smoker, said "Doge Barking at the moon" in a tweet. He also shared a photo of a painting by Spanish artist Joan Miró, which is titled "Dog Barking at the Moon."
Dogecoin is now the world's fifth most valuable cryptocurrency, according to CoinMarketCap. Strong demand for the virtual currency briefly took down Robinhood's crypto trading systems on Thursday, as the platform struggled to process a surge in orders.
Created in 2013 by a pair of software engineers as a joke, the cryptocurrency doesn't have much real-world use outside of a few niche markets, including tipping online artists.
Unlike bitcoin, which has set 21 million as the finite amount of the digital currency, dogecoin has 129 billion coins in circulation and will continue to make new blocks of coins available to mine each year.
That's part of the reason one dogecoin costs less than $1, while each bitcoin costs about $55,000.
— David Goldman and Diksha Madok contributed to this report.