When Is Mother-In-Law’s Day and When Was the Holiday For Spouses’ Mothers Created?

According to a resolution passed by the U.S. House of Representatives in 1981, the fourth Sunday in October is set aside to honor mothers by marriage.

Although the U.S. Senate hasn’t adopted the resolution making the occasion official, the greeting-card industry continues to lobby for Mother-in-Law’s Day and each year about 800,000 cards are sent to spouses’ mothers.