diff --git a/vizier/_src/pyglove/converters.py b/vizier/_src/pyglove/converters.py
index 8626f3aff..f63e8934a 100644
--- a/vizier/_src/pyglove/converters.py
+++ b/vizier/_src/pyglove/converters.py
@@ -559,11 +559,13 @@ def to_tuner_trial(self, vizier_trial: vz.Trial) -> pg.tuning.Trial:
             vizier_trial.final_measurement
         ),
         status=self._to_tuner_trial_status(vizier_trial.status),
-        created_time=int(
+        created_time=int(  # pylint: disable=g-long-ternary
             vizier_trial.creation_time.replace(
                 tzinfo=datetime.timezone.utc
             ).timestamp()
-        ),
+        )
+        if vizier_trial.creation_time
+        else None,
         completed_time=int(  # pylint: disable=g-long-ternary
             vizier_trial.completion_time.replace(
                 tzinfo=datetime.timezone.utc
diff --git a/vizier/_src/pyglove/core.py b/vizier/_src/pyglove/core.py
index 7a5217c20..396685c76 100644
--- a/vizier/_src/pyglove/core.py
+++ b/vizier/_src/pyglove/core.py
@@ -59,6 +59,10 @@ def __init__(
     completed_time = (
         int(trial.completion_time.timestamp()) if trial.completion_time else 0
     )
+    created_time = (
+        int(trial.creation_time.timestamp()) if trial.creation_time else 0
+    )
+
     super().__init__(
         dna=pg.DNA(None),
         id=trial.id,
@@ -67,7 +71,7 @@ def __init__(
             trial.final_measurement
         ),
         status=_trial_status_legacy_value(trial.status),
-        created_time=int(trial.creation_time.timestamp()),
+        created_time=created_time,
         completed_time=completed_time,
         infeasible=trial.infeasible,
         **kwargs,