diff --git a/resources/schema/Operator.md b/resources/schema/Operator.md
index 4b0b650b4..1baadd2a5 100644
--- a/resources/schema/Operator.md
+++ b/resources/schema/Operator.md
@@ -563,9 +563,11 @@ Date check
 
 ### invalid_date
 
-Date check
+The operator performs date validation against complete and partial dates with uncertainty in the following order:
 
-> BRTHDTC is invalid
+1. Attempts to parse using [dateutil.parser.isoparse()](https://dateutil.readthedocs.io/en/stable/parser.html)
+2. If parsing fails and the string contains uncertainty indicators (`/`, `--`, `-:`), validates against an extended ISO 8601 dates regex pattern
+3. If parsing succeeds, dates are still validated against the regex pattern.
 
 ```yaml
 - name: "BRTHDTC"