diff --git a/.github/workflows/create-release-pr.yaml b/.github/workflows/create-release-pr.yaml
index 9bec869..d179809 100644
--- a/.github/workflows/create-release-pr.yaml
+++ b/.github/workflows/create-release-pr.yaml
@@ -20,6 +20,11 @@ on:
         description: Exact version number to target. Only used if bump_type is set to `exact`.
         required: false
         default: ""
+      timezone:
+        type: string
+        description: IANA timezone to use when computing the current date
+        default: "America/Los_Angeles"
+        required: false
 
 jobs:
   prepare-release:
@@ -28,6 +33,7 @@ jobs:
     env:
       BUMP_TYPE: ${{ inputs.bump_type }}
       EXACT_VERSION: ${{ inputs.exact_version }}
+      CHANGELOG_TIMEZONE: ${{ inputs.timezone }}
 
     steps:
       # Get the version of _this_ repository that is in use so that we can use
diff --git a/.github/workflows/pytest.yaml b/.github/workflows/pytest.yaml
index 0761722..1bb1538 100644
--- a/.github/workflows/pytest.yaml
+++ b/.github/workflows/pytest.yaml
@@ -18,7 +18,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.8"
+          - "3.9"
           - "3.12"
 
     steps:
diff --git a/bumpchanges/bump.py b/bumpchanges/bump.py
index 43adefe..d67b75c 100644
--- a/bumpchanges/bump.py
+++ b/bumpchanges/bump.py
@@ -1,18 +1,20 @@
 "Work with CHANGELOG.md files."
 
 import argparse
+import datetime
+import logging
 import os
 import tempfile
+import zoneinfo
 
 from logging import getLogger
-
 from pathlib import Path
 
 from .changelog import Changelog, ChangelogError
 from .logging import setup_logging
 
 
-def update_changelog(changelog_file: Path, repo_url: str, version: str):
+def update_changelog(changelog_file: Path, repo_url: str, version: str, date: datetime.date):
     "Rewrite a CHANGELOG file for a new release."
 
     try:
@@ -21,7 +23,7 @@ def update_changelog(changelog_file: Path, repo_url: str, version: str):
         getLogger(__name__).exception("Could not parse changelog")
         raise
 
-    changelog.update_version(version)
+    changelog.update_version(version, date)
 
     changelog_file.write_text(changelog.render(), encoding="utf-8")
 
@@ -57,7 +59,7 @@ def write_commit_details(version: str):
         bodyfile.write(f"""\
 Update CHANGELOG in preparation for release **{version}**.
 
-Merging this PR will trigger another workflow to create the release tag **v{version}**."
+Merging this PR will trigger another workflow to create the release tag **v{version}**.
 
 | Input | Value |
 | ----- | ----- |
@@ -68,7 +70,7 @@ def write_commit_details(version: str):
 
         outputs["pr_bodyfile"] = bodyfile.name
 
-    outputs["pr_title"] = f"Prepare for version **`{version}`**"
+    outputs["pr_title"] = f"Prepare for version `{version}`"
     outputs["commit_message"] = f"Update CHANGELOG for version `{version}`"
 
     Path(os.environ["GITHUB_OUTPUT"]).write_text(
@@ -87,5 +89,20 @@ def entrypoint():
     args = parser.parse_args()
     setup_logging()
 
-    update_changelog(args.changelog, args.repo_url, args.version)
+    try:
+        input_timezone = os.environ["CHANGELOG_TIMEZONE"]
+        try:
+            tzinfo = zoneinfo.ZoneInfo(input_timezone)
+        except zoneinfo.ZoneInfoNotFoundError:
+            logging.getLogger(__name__).warning(
+                "Time zone `%s` not found! Defaulting to UTC", input_timezone
+            )
+            tzinfo = datetime.timezone.utc
+    except KeyError:
+        logging.getLogger(__name__).notice("No time zone provided, defaulting to UTC")
+        tzinfo = datetime.timezone.utc
+
+    now_date = datetime.datetime.now(tzinfo).date()
+
+    update_changelog(args.changelog, args.repo_url, args.version, now_date)
     write_commit_details(args.version)
diff --git a/bumpchanges/changelog.py b/bumpchanges/changelog.py
index 99bd20a..62cf5b5 100644
--- a/bumpchanges/changelog.py
+++ b/bumpchanges/changelog.py
@@ -3,6 +3,7 @@
 import datetime
 import itertools
 import logging
+import os
 import re
 
 from dataclasses import dataclass, field
@@ -304,7 +305,7 @@ def __init__(self, changelog_file: Path, repo_url: str):
         if not self.versions:
             raise ChangelogError("No versions!")
 
-    def update_version(self, next_version: str):
+    def update_version(self, next_version: str, date: datetime.date):
         "Move all unreleased changes under the new version."
         if not self.versions or self.versions[0].version != "Unreleased":
             logging.getLogger(__name__).warning(
@@ -315,9 +316,8 @@ def update_version(self, next_version: str):
         # Change the version and date of the unreleased section. For now
         # explicitly assume UTC, but that should probably be an input.
         self.versions[0].version = next_version
-        self.versions[0].date = (
-            datetime.datetime.now(datetime.timezone.utc).date().isoformat()
-        )
+        self.versions[0].date = date.isoformat()
+
 
     def render(self) -> str:
         "Render the CHANGELOG to markdown."
diff --git a/pyproject.toml b/pyproject.toml
index ffb735c..8101172 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ dynamic = ["version"]
 
 keywords = ["changelog", "ci"]
 
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 
 dependencies = [
     "linkify-it-py>=2.0.3",
@@ -38,7 +38,7 @@ version-file = "bumpchanges/_version.py"
 legacy_tox_ini = """
 [tox]
 env_list =
-    py3.8
+    py3.9
     py3.12
 
 [testenv]