diff --git a/source/_lovelace/entities.markdown b/source/_lovelace/entities.markdown
index bae810472ce..bb044e2472b 100644
--- a/source/_lovelace/entities.markdown
+++ b/source/_lovelace/entities.markdown
@@ -331,6 +331,10 @@ name:
   required: false
   description: Overwrites friendly name.
   type: string
+format:
+  required: false
+  description: "How the attribute value should be formatted. Currently only supported for timestamp attributes. Valid values are: `relative`, `total`, `date`, `time` and `datetime`."
+  type: string  
 {% endconfiguration %}
 
 ## Example