diff --git a/CHANGELOG.md b/CHANGELOG.md
index e3a36d6..c5ee37e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## UNRELEASED (0.5.4)
+## [0.5.4](https://github.com/brick/date-time/releases/tag/0.5.4) - 2023-10-16
 
 🐛 **Bug fixes**
 
@@ -32,6 +32,10 @@ The `toISOString()` methods return the same result as `__toString()`, but are be
 $date?->toISOString();
 ```
 
+⚡️ **Performance optimizations**
+
+- Most `__toString()` methods got a small performance boost
+
 Thanks to [@gnutix](https://github.com/gnutix)!
 
 ## [0.5.3](https://github.com/brick/date-time/releases/tag/0.5.3) - 2023-09-27