diff --git a/src/eyepy/core/eyemeta.py b/src/eyepy/core/eyemeta.py
index 03342b1..89e89c3 100644
--- a/src/eyepy/core/eyemeta.py
+++ b/src/eyepy/core/eyemeta.py
@@ -26,6 +26,10 @@ def as_dict(self) -> dict:
 
         """
         data = self._store.copy()
+
+        for key in data:
+            if isinstance(data[key], datetime.datetime):
+                data[key] = data[key].isoformat()
         return data
 
     def __getitem__(self, key: str) -> Any: