Another Day instance removed

servant-examples/tutorial/T1.hs

@@ -17,17 +17,12 @@ data User = User
   , registration_date :: Day
   } deriving (Eq, Show, Generic)
 
--- orphan ToJSON instance for Day. necessary to derive one for User
-instance ToJSON Day where
-  -- display a day in YYYY-mm-dd format
-  toJSON d = toJSON (showGregorian d)
-
 instance ToJSON User
 
 type UserAPI = "users" :> Get '[JSON] [User]
 
 users :: [User]
-users = 
+users =
   [ User "Isaac Newton"    372 "isaac@newton.co.uk" (fromGregorian 1683  3 1)
   , User "Albert Einstein" 136 "ae@mc2.org"         (fromGregorian 1905 12 1)
   ]