Parse ISOTimestamps for history in a python < 3.7 compatible way

blink/history.py

@@ -9,7 +9,8 @@ from application.notification import IObserver, NotificationCenter, Notification
 from application.python import Null
 from application.python.types import Singleton
 
-from datetime import date, datetime, timezone
+from datetime import date, timezone
+from dateutil.parser import isoparse
 from dateutil.tz import tzlocal
 from zope.interface import implementer
 
@@ -293,7 +294,7 @@ class MessageHistory(object, metaclass=Singleton):
         timestamp_native = message.timestamp
         timestamp_utc = timestamp_native.replace(tzinfo=timezone.utc)
         message.timestamp = timestamp_utc - message.timestamp.utcoffset()
-        timestamp = datetime.fromisoformat(str(message.timestamp))
+        timestamp = isoparse(str(message.timestamp))
 
         optional_fields = {}
         if state is not None: