diff --git a/agent/learning_graph_render.py b/agent/learning_graph_render.py
index c367cbf7bbb..3602ee270e6 100644
--- a/agent/learning_graph_render.py
+++ b/agent/learning_graph_render.py
@@ -73,7 +73,8 @@ def format_date(ts: Optional[float]) -> str:
     if not ts:
         return "unknown"
     try:
-        return datetime.fromtimestamp(float(ts), tz=timezone.utc).strftime("%-d %b %Y")
+        dt = datetime.fromtimestamp(float(ts), tz=timezone.utc)
+        return f"{dt.day} {dt.strftime('%b %Y')}"
     except (ValueError, OSError, OverflowError):
         return "unknown"