National Twin Day in the United States is observed every year on December 18, so it is only “National Twin Day” today if the current date is December 18.

What is National Twin Day?

  • National Twin Day is a modern awareness/celebration day honoring the special bond between twins and other multiples like triplets.
  • It focuses on the emotional and biological connection between siblings born at (or around) the same time, celebrating their shared experiences.

When it’s celebrated

  • Most recent sources place National Twin Day annually on December 18, with upcoming observances listed on that date for multiple years (e.g., 2025, 2026, 2027).
  • Separately, there is a long‑running Twins Days Festival held in Twinsburg, Ohio, every August, which is related but not the same as National Twin Day itself.

Why there’s confusion

  • Some older or alternate “day” calendars mention early‑August dates because of the Twinsburg festival and earlier informal observances.
  • Newer holiday calendars and awareness‑day sites now consistently list December 18 as the official National Twin Day, clarified in 2019 by at least one national‑day organization.

If today is not December 18 where you are, then no—today is not National Twin Day.

Information gathered from public forums or data available on the internet and portrayed here.