diff --git a/gpt_engineer/learning.py b/gpt_engineer/learning.py
index 3d24e46..6536e00 100644
--- a/gpt_engineer/learning.py
+++ b/gpt_engineer/learning.py
@@ -37,7 +37,7 @@ class Learning:
     feedback: Optional[str]
     session: str
     review: Optional[Review]
-    timestamp: str = field(default_factory=lambda: datetime.now().isoformat())
+    timestamp: str = field(default_factory=lambda: datetime.utcnow().isoformat())
     version: str = "0.3"