National Twin Day

National Twin Day is observed annually on December 18. This day is a dedicated celebration of the unique biological and emotional bond shared by siblings born at the same time, honoring the special connection between them.

History of National Twin Day

The specific observance of National Twin Day on December 18 is a relatively modern addition to the calendar. It was officially proclaimed in 2019 by the National Day Calendar to provide a distinct date for recognizing twins, triplets, and other multiples. While the fascination with twins dates back to ancient mythology—from the Greek gods Apollo and Artemis to the founders of Rome, Romulus and Remus—this specific holiday was established to focus on the personal relationships and shared life experiences of twins in the modern world.

It is important to distinguish this day from the well-known “Twins Days Festival,” which takes place annually in August in Twinsburg, Ohio. While the August event is a large-scale public festival involving parades and contests, the December 18 observance is a broader, often digital or personal celebration that can be observed anywhere. The choice of December 18 provides a winter counterpart to the summer festival, ensuring that the twin community has a moment of recognition during the holiday season, a time when family connections are already at the forefront of people’s minds.

Why is National Twin Day important?

This day highlights one of the most fascinating phenomena in human biology and psychology. Twins often share an unspoken language and a level of empathy that is difficult for non-twins to comprehend. For identical twins, who share nearly 100% of their DNA, the bond can be central to their identity. This holiday validates that deep connection, celebrating the support system that comes with having a partner in life from the very first breath. It is a day to acknowledge that while they are individuals with separate personalities, their shared journey is something rare and powerful.

Furthermore, the day serves as an educational platform regarding the different types of multiples. It helps dispel common myths and encourages learning about the science of fraternal versus identical twinning. It is also a day to support parents of multiples, acknowledging the unique challenges and double blessings they face. By dedicating a day to this demographic, society recognizes the complexity of raising twins and the special dynamics that shape their lives.

• Honors the lifelong support system between twins
• Educates the public on the science of multiple births
• Celebrates the unique “twin language” or cryptophasia
• Recognizes the challenges overcome by parents of multiples
• Distinguishes individual identities within a shared pair

How to Observe National Twin Day

For twins, this is the perfect occasion to reconnect or spend quality time together. If distance is an issue, a long video call to reminisce about shared childhood memories is a great way to mark the date. Many twins use this day to recreate favorite old photos, posing in the same way they did as toddlers to show how much (or how little) they have changed. Wearing matching outfits, often a source of embarrassment in childhood, can be a fun, ironic way to celebrate the day as adults.

Friends and family of twins can participate by sending cards or messages that acknowledge both individuals distinctively. It is a thoughtful gesture to treat them to a meal or an outing where the focus is on their dynamic. For those who are not twins, watching movies or reading books that feature twin characters—such as The Parent Trap or Shakespeare’s The Comedy of Errors—can be an entertaining way to engage with the theme of the holiday.

• Recreate a favorite childhood photo side-by-side
• Wear coordinating or matching outfits for fun
• Share stories of “twin telepathy” on social media
• Watch a movie or documentary featuring twins
• Reach out to the twins in your life with a message

National Twin Day Dates