chore(date): revert time range formatter

src/Handler/Utils/DateTime.hs

@@ -333,29 +333,22 @@ formatTimeRange' :: ( HasLocalTime t, HasLocalTime t'
                  -> t -- ^ Start
                  -> Maybe t' -- ^ End
                  -> m Text
-formatTimeRange' cont proj startT Nothing     = cont proj startT
-formatTimeRange' cont proj startT (Just endT) = do  
+-- In order to abbreviate common same month time ranges, e.g. 24--26.12.23 on must take into account all DateFormatString, as some have the day on the end or feature a weekday
+formatTimeRange' cont proj startT endT = do
+  startT' <- cont proj startT
   let
-    locDayStart = localDay $ toLocalTime startT
-    locDayEnd   = localDay $ toLocalTime endT
-    (yearStart, monthStart, dayStart) = toGregorian locDayStart
-    (yearEnd  , monthEnd  , dayEnd  ) = toGregorian locDayEnd
     endProj = (/\ proj) $ if
-      | locDayStart == locDayEnd
-        -> SelFormatTime      
+      | Just endT' <- endT
+      , ((==) `on` localDay) (toLocalTime startT) (toLocalTime endT')
+      -> SelFormatTime
       | otherwise
-        -> SelFormatDateTime  
-  startT' <- cont    proj startT
-  endT'   <- cont endProj   endT
-  return $ if   
-    | SelFormatDate == endProj
-    ,  yearStart ==  yearEnd
-    , monthStart == monthEnd
-      -> if dayStart == dayEnd
-          then startT'
-          else [st|#{dayStart} - #{endT'}|] -- does not work all date/time format strings!
-    | otherwise 
-      ->       [st|#{startT'} - #{endT'}|]
+      -> SelFormatDateTime
+  endT' <- for endT $ cont endProj
+
+  return $ case endT' of
+    Nothing     -> startT'
+    Just endT'' -> [st|#{startT'} – #{endT''}|]
+
 
 formatTimeRange :: ( HasLocalTime t, HasLocalTime t'
                    , MonadHandler m