Labor Day, celebrated on the first Monday of September, is the only federally recognized holiday in September. Patriot Day and the National Day of Service and Remembrance occur on Sept. 11. Certain Jewish and Muslim holidays are also celebrated in September, depending on the respective religious calendar.
Labor Day was officially recognized in 1887 as a national holiday to honor the American working classes. Patriot Day and the National Day of Service and Remembrance are not recognized as holidays for federal employees. However, a presidential proclamation issued for the day requires flags flown at half-staff and encourages U.S. citizens to observe a moment of silence to honor the terrorist attacks of Sept. 11, 2001.
The Jewish High Holy Days, including Rosh Hashanah and Yom Kippur, typically occur in September, though the exact dates depend on the Hebrew calendar. Eid al-Adha, or Festival of the Sacrifice, is a Muslim holiday that may occur in September, though the Muslim calendar sometimes places this holiday in October.