Update changelog

CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Changed
+
+- Set the time zone of the server to UTC
+
+### Fixed
+
+- Fixed the start date of the date ranges in the portfolio performance calculation for instances in time zones other than UTC
+
 ## 3.82.0 - 2026-10-09
 
 ### Added