fix(time): midnight timezone conversion bug eliminated

src/Handler/Utils/DateTime.hs

@@ -62,7 +62,7 @@ localTimeToUTC = TZ.localTimeToUTCFull appTZ
 localTimeToUTCSimple :: LocalTime -> UTCTime
 localTimeToUTCSimple = TZ.localTimeToUTCTZ appTZ
 
--- | Local midnight of given day
+-- | Local midnight of given day; use Utils.DateTime.utctDayMidnight :: Day -> UTCTime instead to avoid Timezone conversion!
 toMidnight :: Day -> UTCTime
 toMidnight = toTimeOfDay 0 0 0
 

src/Handler/Utils/Qualification.hs

@@ -17,7 +17,6 @@ import qualified Data.Text as Text
 import qualified Database.Esqueleto.Experimental as E   -- might need TypeApplications Lang-Pragma
 import qualified Database.Esqueleto.Utils as E
 
-import Handler.Utils.DateTime (toMidnight)
 import Handler.Utils.Widgets  (statusHtml)
 
 statusQualificationBlock :: Bool -> Html
@@ -152,7 +151,7 @@ upsertQualificationUser  qualificationUserQualification qualificationUserLastRef
     QualificationUser
       { qualificationUserFirstHeld        = qualificationUserLastRefresh      
       , qualificationUserScheduleRenewal  = fromMaybe True mbScheduleRenewal
-      , qualificationUserLastNotified     = toMidnight qualificationUserLastRefresh
+      , qualificationUserLastNotified     = utctDayMidnight qualificationUserLastRefresh
       , ..
       }
     (

src/Jobs/Handler/LMS.hs

@@ -410,7 +410,7 @@ dispatchJobLmsResults qid = JobHandlerAtomic act
 
               update luid
                 [ LmsUserStatus     =. Just LmsSuccess
-                , LmsUserStatusDay  =. Just (toMidnight lmsResultSuccess)
+                , LmsUserStatusDay  =. Just (utctDayMidnight lmsResultSuccess)
                 , LmsUserReceived   =. Just lmsResultTimestamp
                 ]
               return Nothing
@@ -422,7 +422,7 @@ dispatchJobLmsResults qid = JobHandlerAtomic act
           audit TransactionLmsSuccess -- always log success, since this is only transmitted once
             { transactionQualification = qid
             , transactionLmsIdent      = lmsUserIdent
-            , transactionLmsDay        = toMidnight lmsResultSuccess
+            , transactionLmsDay        = utctDayMidnight lmsResultSuccess
             , transactionLmsUser       = lmsUserUser
             , transactionNote          = note
             , transactionReceived      = lmsResultTimestamp

src/Model/Types/Lms.hs

@@ -159,9 +159,6 @@ instance Csv.FromField LmsTimestamp where
   parseField i = do 
       s <- Csv.parseField i 
       d <- Time.parseTimeM True Time.defaultTimeLocale lmsTimestampFormat s
-            <|> (toMidnight <$> Time.parseTimeM True Time.defaultTimeLocale lmsDayFormat s)
+            <|> (utctDayMidnight <$> Time.parseTimeM True Time.defaultTimeLocale lmsDayFormat s)
             <|> iso8601ParseM s -- Know-How AG considers supplying iso8601 dates in the future
       return $ LmsTimestamp d
-    where
-      toMidnight :: Day -> UTCTime
-      toMidnight d = UTCTime { utctDay = d, utctDayTime = toEnum 0 }

src/Utils/DateTime.hs

@@ -19,6 +19,7 @@ module Utils.DateTime
   , diffMinute, diffHour, diffDay
   , module Zones  
   , day
+  , utctDayMidnight
   ) where
 
 import ClassyPrelude.Yesod hiding (lift, Proxy(..))
@@ -181,3 +182,7 @@ day = QuasiQuoter{..}
     quoteType = error "day used as type"
     quoteDec = error "day used as declaration"
     quoteExp dStr = maybe (fail $ "Could not parse ISO8601 day: “" <> dStr <> "”") (lift :: Day -> Q Exp) $ Time.iso8601ParseM dStr
+
+-- | use Handler.Utils.DateTime.toMidnight instead, if the local timezone is to be accounted for
+utctDayMidnight :: Day -> UTCTime
+utctDayMidnight d = UTCTime { utctDayTime = 0, utctDay = d }