diff --git a/src/Handler/Course/ParticipantInvite.hs b/src/Handler/Course/ParticipantInvite.hs
index d31cd0d41..4bdf04021 100644
--- a/src/Handler/Course/ParticipantInvite.hs
+++ b/src/Handler/Course/ParticipantInvite.hs
@@ -49,7 +49,7 @@ tutorialTemplateNames Nothing     = ["Vorlage", "Template"]
 tutorialTemplateNames (Just name) = [prefixes <> suffixes | prefixes <- tutorialTemplateNames Nothing, suffixes <- [mempty, tutorialTypeSeparator <> name]]
 
 tutorialDefaultName :: Maybe TutorialType -> Day -> TutorialName
-tutorialDefaultName Nothing     = CI.mk . tshow  -- Don't use user date display setting, so that tutorial default names conform to all users
+tutorialDefaultName Nothing     = string2citext . formatTime defaultTimeLocale "%y_%m_%d" -- Don't use user date display setting, so that tutorial default names conform to all users
 tutorialDefaultName (Just ttyp) = 
   let prefix = CI.mk $ snd $ Text.breakOnEnd (CI.original tutorialTypeSeparator) $ CI.original ttyp
   in  (<> (tutorialTypeSeparator <> prefix)) . tutorialDefaultName Nothing
diff --git a/src/Utils.hs b/src/Utils.hs
index dc9e8199a..4f8b5ff03 100644
--- a/src/Utils.hs
+++ b/src/Utils.hs
@@ -312,6 +312,9 @@ citext2lower = Text.toLower . CI.original
 citext2string :: CI Text -> String 
 citext2string = Text.unpack . CI.original
 
+string2citext :: String -> CI Text
+string2citext = CI.mk . Text.pack
+
 -- | Convert or remove all non-ascii  characters, e.g. for filenames 
 text2asciiAlphaNum :: Text -> Text
 text2asciiAlphaNum = Text.filter (\c -> Char.isAlphaNum c && Char.isAscii c)