Update CHANGELOG.md

Author: oliviertassinari

Diff for: CHANGELOG.md

@@ -3,7 +3,7 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
-## [4.0.0-alpha.1](https://github.com/mui-org/material-ui-x/compare/v0.1.67...v4.0.0-alpha.1) (Sep 15, 2020)
+## [4.0.0-alpha.1](https://github.com/mui-org/material-ui-x/compare/v0.1.67...v4.0.0-alpha.1) (Sep 17, 2020)
 
 This is the first public alpha release of the component after 6 months of development since the initial commit (March 15th 2020).
 `@material-ui/data-grid` is licensed under MIT while `@material-ui/x-grid` is licensed under a commercial license.