diff --git a/Data/Time/Calendar/Days.hs b/Data/Time/Calendar/Days.hs
--- a/Data/Time/Calendar/Days.hs
+++ b/Data/Time/Calendar/Days.hs
@@ -1,3 +1,5 @@
+{-# OPTIONS -fno-warn-unused-imports #-}
+#include "HsConfigure.h"
 -- #hide
 module Data.Time.Calendar.Days
 (
@@ -7,9 +9,18 @@
 
 import Data.Ix
 import Data.Typeable
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | The Modified Julian Day is a standard count of days, with zero being the day 1858-11-17.
-newtype Day = ModifiedJulianDay {toModifiedJulianDay :: Integer} deriving (Eq,Ord)
+newtype Day = ModifiedJulianDay {toModifiedJulianDay :: Integer} deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+    ,Data
+#endif
+#endif
+    )
 
 instance Typeable Day where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.Calendar.Days.Day") []
diff --git a/Data/Time/Clock/Scale.hs b/Data/Time/Clock/Scale.hs
--- a/Data/Time/Clock/Scale.hs
+++ b/Data/Time/Clock/Scale.hs
@@ -1,3 +1,5 @@
+{-# OPTIONS -fno-warn-unused-imports #-}
+#include "HsConfigure.h"
 -- #hide
 module Data.Time.Clock.Scale
 (
@@ -13,10 +15,19 @@
 import Data.Ratio ((%))
 import Data.Fixed
 import Data.Typeable
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | The Modified Julian Date is the day with the fraction of the day, measured from UT midnight.
 -- It's used to represent UT1, which is time as measured by the earth's rotation, adjusted for various wobbles.
-newtype UniversalTime = ModJulianDate {getModJulianDate :: Rational} deriving (Eq,Ord)
+newtype UniversalTime = ModJulianDate {getModJulianDate :: Rational} deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+    ,Data
+#endif
+#endif
+    )
 
 instance Typeable UniversalTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.Clock.Scale.UniversalTime") []
@@ -24,7 +35,16 @@
 -- | This is a length of time, as measured by a clock.
 -- Conversion functions will treat it as seconds.
 -- It has a precision of 10^-12 s.
-newtype DiffTime = MkDiffTime Pico deriving (Eq,Ord)
+newtype DiffTime = MkDiffTime Pico deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    ,Data
+#else
+#endif
+#endif
+#endif
+    )
 
 instance Typeable DiffTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.Clock.Scale.DiffTime") []
diff --git a/Data/Time/Clock/TAI.hs b/Data/Time/Clock/TAI.hs
--- a/Data/Time/Clock/TAI.hs
+++ b/Data/Time/Clock/TAI.hs
@@ -1,3 +1,5 @@
+{-# OPTIONS -fno-warn-unused-imports #-}
+#include "HsConfigure.h"
 -- | TAI and leap-second tables for converting to UTC: most people won't need this module.
 module Data.Time.Clock.TAI
 (
@@ -18,9 +20,20 @@
 import Data.Time.Clock
 import Data.Typeable
 import Data.Fixed
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | AbsoluteTime is TAI, time as measured by a clock.
-newtype AbsoluteTime = MkAbsoluteTime {unAbsoluteTime :: DiffTime} deriving (Eq,Ord)
+newtype AbsoluteTime = MkAbsoluteTime {unAbsoluteTime :: DiffTime} deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    ,Data
+#endif
+#endif
+#endif
+    )
 
 instance Typeable AbsoluteTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.Clock.TAI.AbsoluteTime") []
diff --git a/Data/Time/Clock/UTC.hs b/Data/Time/Clock/UTC.hs
--- a/Data/Time/Clock/UTC.hs
+++ b/Data/Time/Clock/UTC.hs
@@ -1,3 +1,5 @@
+{-# OPTIONS -fno-warn-unused-imports #-}
+#include "HsConfigure.h"
 -- #hide
 module Data.Time.Clock.UTC
 (
@@ -17,6 +19,9 @@
 import Data.Time.Clock.Scale
 import Data.Fixed
 import Data.Typeable
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | This is the simplest representation of UTC.
 -- It consists of the day number, and a time offset from midnight.
@@ -27,6 +32,13 @@
 	-- | the time from midnight, 0 <= t < 86401s (because of leap-seconds)
 	utctDayTime :: DiffTime
 }
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    deriving (Data)
+#endif
+#endif
+#endif
 
 instance Typeable UTCTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.Clock.UTC.UTCTime") []
@@ -45,7 +57,15 @@
 -- It ignores leap-seconds, so it's not necessarily a fixed amount of clock time.
 -- For instance, 23:00 UTC + 2 hours of NominalDiffTime = 01:00 UTC (+ 1 day),
 -- regardless of whether a leap-second intervened.
-newtype NominalDiffTime = MkNominalDiffTime Pico deriving (Eq,Ord)
+newtype NominalDiffTime = MkNominalDiffTime Pico deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    ,Data
+#endif
+#endif
+#endif
+    )
 
 instance Typeable NominalDiffTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.Clock.UTC.NominalDiffTime") []
diff --git a/Data/Time/Format/Parse.hs b/Data/Time/Format/Parse.hs
--- a/Data/Time/Format/Parse.hs
+++ b/Data/Time/Format/Parse.hs
@@ -1,10 +1,13 @@
 {-# OPTIONS -fno-warn-orphans #-}
+#include "HsConfigure.h"
 
 -- #hide
 module Data.Time.Format.Parse 
     (
     -- * UNIX-style parsing
+#if LANGUAGE_Rank2Types
     parseTime, readTime, readsTime,
+#endif
     ParseTime(..)
     ) where
 
@@ -15,16 +18,20 @@
 import Data.Time.Calendar.WeekDate
 import Data.Time.LocalTime
 
+#if LANGUAGE_Rank2Types
 import Control.Monad
+#endif
 import Data.Char
 import Data.Fixed
 import Data.List
 import Data.Maybe
 import Data.Ratio
 import System.Locale
+#if LANGUAGE_Rank2Types
 import Text.ParserCombinators.ReadP hiding (char, string)
-
+#endif
 
+#if LANGUAGE_Rank2Types
 -- | Case-insensitive version of 'Text.ParserCombinators.ReadP.char'.
 char :: Char -> ReadP Char
 char c = satisfy (\x -> toUpper c == toUpper x)
@@ -33,8 +40,9 @@
 string this = do s <- look; scan this s
   where
     scan []     _                               = do return this
-    scan (x:xs) (y:ys) | toUpper x == toUpper y = do get; scan xs ys
+    scan (x:xs) (y:ys) | toUpper x == toUpper y = do _ <- get; scan xs ys
     scan _      _                               = do pfail
+#endif
 -- | Convert string to upper case.
 up :: String -> String
 up = map toUpper
@@ -52,6 +60,7 @@
                                  -- corresponding part of the input.
               -> t
 
+#if LANGUAGE_Rank2Types
 -- | Parses a time value given a format string. Supports the same %-codes as
 -- 'formatTime'. Leading and trailing whitespace is accepted. Case is not
 -- significant. Some variations in the input are accepted:
@@ -179,6 +188,7 @@
                    optional (char ':')
                    m <- digits 2
                    return (s:h++m)
+#endif
 
 --
 -- * Instances for the time package types
@@ -319,6 +329,7 @@
 
 -- * Read instances for time package types
 
+#if LANGUAGE_Rank2Types
 instance Read Day where
     readsPrec _ = readParen False $ readsTime defaultTimeLocale "%Y-%m-%d"
 
@@ -337,6 +348,7 @@
 
 instance Read UTCTime where
     readsPrec n s = [ (zonedTimeToUTC t, r) | (t,r) <- readsPrec n s ]
+#endif
 
 readTzOffset :: String -> Int
 readTzOffset str =
diff --git a/Data/Time/LocalTime/LocalTime.hs b/Data/Time/LocalTime/LocalTime.hs
--- a/Data/Time/LocalTime/LocalTime.hs
+++ b/Data/Time/LocalTime/LocalTime.hs
@@ -1,4 +1,5 @@
-{-# OPTIONS -fno-warn-orphans #-}
+{-# OPTIONS -fno-warn-orphans -fno-warn-unused-imports #-}
+#include "HsConfigure.h"
 
 -- #hide
 module Data.Time.LocalTime.LocalTime
@@ -17,6 +18,9 @@
 import Data.Time.Calendar
 import Data.Time.Clock
 import Data.Typeable
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | A simple day and time aggregate, where the day is of the specified parameter,
 -- and the time is a TimeOfDay.
@@ -25,7 +29,15 @@
 data LocalTime = LocalTime {
 	localDay    :: Day,
 	localTimeOfDay   :: TimeOfDay
-} deriving (Eq,Ord)
+} deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    ,Data
+#endif
+#endif
+#endif
+    )
 
 instance Typeable LocalTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.LocalTime.LocalTime.LocalTime") []
@@ -59,6 +71,13 @@
 	zonedTimeToLocalTime :: LocalTime,
 	zonedTimeZone :: TimeZone
 }
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    deriving (Data)
+#endif
+#endif
+#endif
 
 instance Typeable ZonedTime where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.LocalTime.LocalTime.ZonedTime") []
diff --git a/Data/Time/LocalTime/TimeOfDay.hs b/Data/Time/LocalTime/TimeOfDay.hs
--- a/Data/Time/LocalTime/TimeOfDay.hs
+++ b/Data/Time/LocalTime/TimeOfDay.hs
@@ -1,3 +1,5 @@
+{-# OPTIONS -fno-warn-unused-imports #-}
+#include "HsConfigure.h"
 -- #hide
 module Data.Time.LocalTime.TimeOfDay
 (
@@ -13,6 +15,9 @@
 import Data.Time.Clock
 import Data.Typeable
 import Data.Fixed
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | Time of day as represented in hour, minute and second (with picoseconds), typically used to express local time of day.
 data TimeOfDay = TimeOfDay {
@@ -23,7 +28,15 @@
 	-- | Note that 0 <= todSec < 61, accomodating leap seconds.
 	-- Any local minute may have a leap second, since leap seconds happen in all zones simultaneously
 	todSec     :: Pico
-} deriving (Eq,Ord)
+} deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+#if HAS_DataPico
+    ,Data
+#endif
+#endif
+#endif
+    )
 
 instance Typeable TimeOfDay where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.LocalTime.TimeOfDay.TimeOfDay") []
@@ -41,9 +54,9 @@
 
 makeTimeOfDayValid :: Int -> Int -> Pico -> Maybe TimeOfDay
 makeTimeOfDayValid h m s = do
-	clipValid 0 23 h
-	clipValid 0 59 m
-	clipValid 0 60.999999999999 s
+	_ <- clipValid 0 23 h
+	_ <- clipValid 0 59 m
+	_ <- clipValid 0 60.999999999999 s
 	return (TimeOfDay h m s)
 
 -- | Convert a ToD in UTC to a ToD in some timezone, together with a day adjustment.
diff --git a/Data/Time/LocalTime/TimeZone.hs b/Data/Time/LocalTime/TimeZone.hs
--- a/Data/Time/LocalTime/TimeZone.hs
+++ b/Data/Time/LocalTime/TimeZone.hs
@@ -1,4 +1,6 @@
+{-# OPTIONS -fno-warn-unused-imports #-}
 {-# LANGUAGE ForeignFunctionInterface #-}
+#include "HsConfigure.h"
 
 -- #hide
 module Data.Time.LocalTime.TimeZone
@@ -18,6 +20,9 @@
 import Foreign
 import Foreign.C
 import Data.Typeable
+#if LANGUAGE_Rank2Types
+import Data.Data
+#endif
 
 -- | A TimeZone is a whole number of minutes offset from UTC, together with a name and a \"just for summer\" flag.
 data TimeZone = TimeZone {
@@ -27,7 +32,13 @@
 	timeZoneSummerOnly :: Bool,
 	-- | The name of the zone, typically a three- or four-letter acronym.
 	timeZoneName :: String
-} deriving (Eq,Ord)
+} deriving (Eq,Ord
+#if LANGUAGE_DeriveDataTypeable
+#if LANGUAGE_Rank2Types
+    ,Data
+#endif
+#endif
+    )
 
 instance Typeable TimeZone where
 	typeOf _ = mkTyConApp (mkTyCon "Data.Time.LocalTime.TimeZone.TimeZone") []
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-TimeLib is Copyright (c) Ashley Yakeley, 2004-2007.
+TimeLib is Copyright (c) Ashley Yakeley, 2004-2010.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
diff --git a/time.cabal b/time.cabal
--- a/time.cabal
+++ b/time.cabal
@@ -1,5 +1,5 @@
 name:           time
-version:        1.1.4
+version:        1.2
 stability:      stable
 license:        BSD3
 license-file:   LICENSE
@@ -28,6 +28,14 @@
 library
 {
     build-depends: base == 4.*, old-locale
+    ghc-options: -Wall
+    if impl(ghc)
+        extensions: Rank2Types DeriveDataTypeable StandaloneDeriving
+        cpp-options: -DLANGUAGE_Rank2Types -DLANGUAGE_DeriveDataTypeable -DLANGUAGE_StandaloneDeriving
+    else
+        if impl(hugs)
+            extensions: Rank2Types
+            cpp-options: -DLANGUAGE_Rank2Types
     if os(windows)
         build-depends: Win32
     exposed-modules: