From Wikipedia: The modern Mother's Day holiday was created by Anna Jarvis as a day for each family to honor its mother, and it's now celebrated on various days in many places around the world. It complements Father's Day, the celebration honoring fathers.

This holiday is relatively modern, being created at the start of the 20th century, and should not be confused with the early pagan and Christian traditions honoring mothers, or with the 16th century celebration of Mothering Sunday, which is also known as Mother's Day in the UK.

In most countries the Mother's Day celebration is a recent holiday derived from the original US celebration. Exceptions are, for example, the Mothering Sunday holiday in the UK.