5 interesting facts about Mother's Day

1. One celebration, different dates

Many countries have a day set aside to celebrate mothers. However, not all of them fall on the second Sunday of May, as in the United States. 

Some countries, like Australia and Canada, observe the holiday on the same day as the U.S. However, other nations have different methods of picking the day.

"It is held exactly three weeks before Easter Sunday in the United Kingdom," noted the website timeanddate.com.

"Mother's Day is an annual public holiday in countries such as Costa Rica (Aug. 15, on the same day as Assumption Day), Georgia (March 3), Samoa (second Monday of May), and Thailand (Aug. 12)."

And some countries have it on the same date each year. One example is El Salvador, which celebrates the "Dia de Las Madres" on May 10 every year.