diff --git a/tests/reports/test_pr_reporting.py b/tests/reports/test_pr_reporting.py
index 9ddd84b..31e3b8c 100644
--- a/tests/reports/test_pr_reporting.py
+++ b/tests/reports/test_pr_reporting.py
@@ -12,7 +12,7 @@
 from __future__ import annotations
 
 import csv
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone
 from io import StringIO
 from pathlib import Path
 from typing import Any
@@ -105,8 +105,8 @@ def review_prs(recent_date: datetime) -> list[dict[str, Any]]:
             "title": "Add tests",
             "author": "bob",
             "canonical_id": "bob@example.com",
-            "created_at": recent_date.replace(day=recent_date.day + 1),
-            "merged_at": recent_date.replace(day=recent_date.day + 1, hour=14),
+            "created_at": recent_date + timedelta(days=1),
+            "merged_at": (recent_date + timedelta(days=1)).replace(hour=14),
             "additions": 150,
             "deletions": 0,
             "changed_files": 6,
@@ -126,8 +126,8 @@ def review_prs(recent_date: datetime) -> list[dict[str, Any]]:
             "title": "Update docs",
             "author": "alice",
             "canonical_id": "alice@example.com",
-            "created_at": recent_date.replace(day=recent_date.day + 2),
-            "merged_at": recent_date.replace(day=recent_date.day + 2, hour=11),
+            "created_at": recent_date + timedelta(days=2),
+            "merged_at": (recent_date + timedelta(days=2)).replace(hour=11),
             "additions": 30,
             "deletions": 5,
             "changed_files": 2,