diff --git a/gcn/notices/core/DateTime.schema.json b/gcn/notices/core/DateTime.schema.json
index d523698..d816a8c 100644
--- a/gcn/notices/core/DateTime.schema.json
+++ b/gcn/notices/core/DateTime.schema.json
@@ -9,6 +9,12 @@
       "type": "string",
       "description": "Time of the trigger [ISO 8601], ex YYYY-MM-DDTHH:MM:SS.ssssssZ"
     },
+    "trigger_time_error": {
+      "type": "array",
+      "items": { "type": "number" },
+      "maxItems": 2,
+      "description": "Trigger time uncertainty [s, 1-sigma], with optional asymmetric uncertainty"
+    },
     "observation_start": {
       "type": "string",
       "description": "Start time of the observation [ISO 8601]"