September 21 Holidays & Observances
5 holidays observed on September 21 in the 2026–2030 window.
Floating holidays on September 21
These observances only land on September 21 in certain years.
| Holiday | 2026 | 2027 | 2028 | 2029 | 2030 |
|---|---|---|---|---|---|
| Yom Kippur | Sep 21 · Mon | — | — | — | — |
| International Red Panda Day | — | — | — | — | Sep 21 · Sat |
View all September holidays
See every observance across September in one monthly calendar.
September calendar →September 21 — quick answers
- How many holidays fall on September 21?
- In the 2026–2030 window, 5 holidays and observance fall on September 21: International Day of Peace, Yom Kippur, World Alzheimer's Day, International Red Panda Day, Malta Independence Day.
- What is celebrated on September 21?
- September 21 is home to International Day of Peace, Yom Kippur, World Alzheimer's Day and other observances. Each one has its own page with history and a live countdown.
- Are any September 21 holidays public holidays?
- None of the observances on September 21 are US federal holidays; they are celebrated informally by people, brands and communities.