Father's Day is a holiday where sons and daughters show appreciation for all the hard work their fathers do. It was founded in 1910 by Sonora Smart Dodd in order to honor her father, a Civil War veteran who had raised his six children alone after his wife died giving birth to their seventh child. It is now celebrated around the world as an opportunity to recognize and celebrate fathers everywhere.

Father's Day is celebrated in over 50 countries around the world, although not on the same day. In most countries, it falls on the third Sunday of June though some celebrate it in March or May. Here are 10 facts about Father's Day you may not know.

1. The first proposed observance of a Father's Day was by Sonora Smart Dodd from Spokane, Washington, who wanted to honor her father - William Jackson Smart - a Civil War veteran and a single parent raising six children after his wife died during childbirth.

2. The original suggested date for Father's Day was June 5th, 1910; however, the official holiday was declared in 1924 by President Coolidge and finally established as an annual event in 1966 when President Johnson signed it into law.

3. The most popular gift given on Father's Day is a necktie - any guesses why?

4. The first Father's Day card was produced by the Hallmark Company in 1910, and more than 85 million cards are now sent every year.

5. Add some flair to your gift this year with a personalized beer mug or t-shirt - an increasingly popular item on modern-day wishlists!

6. In some countries, such as Australia and New Zealand, Father's Day is called "Special Man's Day."

7. Finland celebrates Father's Day as "Isänpäivä" on the second Sunday of November.

8. Father's Day in Thailand is known as "King's Birthday," as this day marks the birthday of King Bhumibol Adulyadej, the father and King of all Thais.

9. The largest Father's Day celebration takes place in Croatia, where a 'Grandpa Marathon' is held annually to honor fathers.

10. In Spain, Father's Day - also known as "El Día del Padre" - falls on March 19th to celebrate St Joseph's Day, or "Día de San José." 

No matter how you celebrate, Father's Day is a special occasion to honor the fathers and father figures in our lives.