| Date | Weekday | Event | Country | Type |
|---|---|---|---|---|
| 21 Sep | Sunday | Independence Day | Public | |
| 21 Sep | Sunday | Day of the Walloon Region | Belgium | Not public |
| 21 Sep | Sunday | Federal Day of Thanksgiving, Repentance and Prayer | Switzerland | Public |
| 21 Sep | Sunday | Kwame Nkrumah Memorial Day | Ghana | Public |
| 21 Sep | Sunday | Customs Service Day | Poland | Not public |
| 21 Sep | Sunday | International Day of Peace | global | Other |