| date | entity | event | name |
|---|---|---|---|
| 21/04/1891 | fabergeegg | Year of acquisition | Memory of Azov |
| 21/04/2000 | flag | date Adopted | Flag of Sevastopol |
| 21/04/1998 | organization | date founded | Institut national de la statistique |
| 21/04/2004 | organization | date founded | OWASP |
| 21/04/1921 | organization | date founded | Eno Center for Transportation |