diff --git a/README.md b/README.md
index dbe4fb0..f19fde8 100644
--- a/README.md
+++ b/README.md
@@ -19,3 +19,5 @@ optional arguments:
   -t FORMAT, --timestamp-format FORMAT
                      format of timestamp, default: %Y%m%d
 ```
+
+For a complete timestamp format description, see the python strftime() documentation: <https://docs.python.org/3/library/datetime.html#strftime-strptime-behavior>
diff --git a/clean-backups.py b/clean-backups.py
index 7863c88..532230b 100755
--- a/clean-backups.py
+++ b/clean-backups.py
@@ -130,7 +130,12 @@ class BackupFile():
             self.remove(force_remove = force_remove)
 
 # Argument parser
-parser = argparse.ArgumentParser(description="Cleanup old backups")
+parser = argparse.ArgumentParser(
+    description = "Cleanup old backups",
+    epilog = "For a complete timestamp format description, see the python strftime() " +
+             "documentation: https://docs.python.org/3/library/datetime.html" +
+             "#strftime-strptime-behavior"
+)
 # path argument
 parser.add_argument(
     "path",
diff --git a/tests/filegenerator.py b/tests/filegenerator.py
index 3012b71..b2208b1 100755
--- a/tests/filegenerator.py
+++ b/tests/filegenerator.py
@@ -13,7 +13,12 @@ DEFAULT_SUFFIX = ".bak"
 DEFAULT_TIMESTAMP_FORMAT = "%Y%m%d"
 
 # Argument parser
-parser = argparse.ArgumentParser(description="Cleanup old backups")
+parser = argparse.ArgumentParser(
+    description="Cleanup old backups",
+    epilog = "For a complete timestamp format description, see the python strftime() " +
+             "documentation: https://docs.python.org/3/library/datetime.html" +
+             "#strftime-strptime-behavior"
+)
 # path argument
 parser.add_argument(
     "path",