Add time validator for auto-conversion from float to datetime

aleph_message/models/__init__.py

@@ -254,6 +254,13 @@ def check_confirmed(cls, v, values):
             raise ValueError("Message cannot be 'confirmed' without 'confirmations'")
         return v
 
+    @validator("time")
+    def check_time(cls, v):
+        if isinstance(v, float):
+            v = datetime.datetime.fromtimestamp(v)
+        assert isinstance(v, datetime.datetime)
+        return v
+
     class Config:
         extra = Extra.forbid