Update CHANGELOG.md

Author: norberttech

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+## [0.6.0] - 2020-10-23
+- Restore default timezone in Calendar Extension #30
+
 ## [0.5.0] - 2020-10-23
 - Take timezone from calendar instance when not provided to aeon_datetime_format #29