World Penguin Day began with Antarctica researchers and a California man

April 25 (UPI) -- World Penguin Day, celebrated annually on April 25, began with researchers in Antarctica and a man in California whose wife loved penguins.

The holiday was suggested by U.S. researchers based at McMurdo Station in Antarctica, where they documented a colony of Adelie penguins returned from spending months at sea on April 25 for multiple consecutive years.

The scientists began planning celebrations to welcome the penguins on April 25.

The day became a holiday in 1972, when Gerry Wallace of Alamogordo, Calif., marked the date in his wife's calendar as "Penguin Day." Wallace's wife, Aleta, published the holiday in a local newsletter, and it was celebrated as a local holiday the following year.

Other holidays and observances for April 25 include DNA Day, National Plumbers Day, National Zucchini Bread Day, National Telephone Day and National Mani-Pedi Day.