diff --git a/doc/source/admin/useful_scripts.rst b/doc/source/admin/useful_scripts.rst
index 1b3438588372..9fe85c291008 100644
--- a/doc/source/admin/useful_scripts.rst
+++ b/doc/source/admin/useful_scripts.rst
@@ -35,4 +35,4 @@ To safely delete unused histories and their associated records, please use the `
     optional arguments:
       -h, --help         show this help message and exit
       --batch BATCH      batch size
-      --created CREATED  most recent created date/time in ISO format
+      --created CREATED  most recent created date/time in ISO format (for example, March 11, 1952 is represented as '1952-03-11')
diff --git a/lib/galaxy/model/scripts/prune_history_table.py b/lib/galaxy/model/scripts/prune_history_table.py
index 1d326154c7a5..d4c976b050d7 100644
--- a/lib/galaxy/model/scripts/prune_history_table.py
+++ b/lib/galaxy/model/scripts/prune_history_table.py
@@ -30,7 +30,9 @@ def _get_parser():
     parser = argparse.ArgumentParser(description=DESCRIPTION)
     parser.add_argument("--batch", type=int, help="batch size")
     parser.add_argument(
-        "--created", type=datetime.datetime.fromisoformat, help="most recent created date/time in ISO format"
+        "--created",
+        type=datetime.datetime.fromisoformat,
+        help="most recent created date/time in ISO format  (for example, March 11, 1952 is represented as '1952-03-11')",
     )
     return parser