Is March 8 Women's Day considered a traditional Chinese holiday?

No. March 8 is Women's Day, a national holiday for women.

International Women's Day is a holiday celebrated in many countries around the world. It is a day when women are recognized for their achievements, regardless of their nationality, ethnicity, language, culture, economic status and political stance. Since then, International Women's Day has become a global women's holiday that has taken on new significance for women in developed and developing countries alike.

Origins

The United Nations web page on International Women's Day attributes the origins of International Women's Day to a series of women's movement events in the early part of the twentieth century, including:

In 1909, the Socialists in the United States of America established February 28th as a day to celebrate women's rights. In 1909, the Socialists designated February 28th as National Women's Day; in 1910, more than 100 women delegates from 17 countries, led by Clara Chaitkin at the Copenhagen Conference of the Second International, planned to establish an International Women's Day.

On March 19, 1911, more than one million women gathered in Austria, Denmark, Germany and Switzerland to celebrate International Women's Day; on the last Sunday of February 1913, Russian women celebrated their International Women's Day with a demonstration; on March 8, 1914, women in many European countries held anti-war demonstrations.

On March 8, 1917 (February 23rd in the Russian calendar), Russian women went on strike in memory of the nearly two million Russian women who had lost their lives in World War I. Four days later, the Tsar was forced to abdicate, and the Provisional Government declared that women would be given the right to vote.

This series of feminist movements in Europe and the Americas at the beginning of the 20th century led to the birth of International Women's Day.