The burger-chain sells nearly 25% of their wild-caught Alaska Pollock fish sandwiches during Lent, when many Catholics forgo meat on Fridays, according to spokeswoman Becca Hary.

The Filet-O-Fish sandwich owes its existence on the McDonald's menu to a Cincinnati-franchise owner who noticed in the 1960s that he was losing Catholic customers on Fridays due to the burger-only options. Since its inception, the sandwich has been a staple for many over the last 55 years.

On social media, many noted that Lent, which begins on March 1, is jokingly dubbed "Filet-O-Fish season" in some communities.