test unix: fix time-zone test

lib/Data/Time/LocalTime/Internal/TimeZone.hs

@@ -101,7 +101,7 @@ toCTime t = let
     tt = fromIntegral t
     t' = fromIntegral tt
     -- there's no instance Bounded CTime, so this is the easiest way to check for overflow
-    in if t' == t then return $ CTime tt else fail "Data.Time.LocalTime.Internal.TimeZone.toCTime: Overflow" where
+    in if t' == t then return $ CTime tt else fail "Data.Time.LocalTime.Internal.TimeZone.toCTime: Overflow"
 
 -- | Get the local time-zone for a given time (varying as per summertime adjustments).
 getTimeZoneSystem :: SystemTime -> IO TimeZone

test/unix/Test/LocalTime/TimeZone.hs

@@ -9,7 +9,7 @@ import Test.Tasty.HUnit
 
 testTimeZone :: TestTree
 testTimeZone = testCase "getTimeZone respects TZ env var" $ do
-    let epoch = UTCTime (ModifiedJulianDay 0) 0
+    let epoch = UTCTime (ModifiedJulianDay 57000) 0
     putEnv "TZ=UTC+0"
     zone1 <- getTimeZone epoch
     putEnv "TZ=EST+5"