diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,9 @@
 # Change Log
 
+## [1.9.1]
+- new functions secondsToNominalDiffTime & nominalDiffTimeToSeconds
+- expose FormatTime and ParseTime in Data.Time.Format.Internal
+
 ## [1.9]
 - new conversion functions timeToDaysAndTimeOfDay & daysAndTimeOfDayToTime
 - new DayOfWeek type
diff --git a/configure.ac b/configure.ac
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([Haskell time package], [1.9], [ashley@semantic.org], [time])
+AC_INIT([Haskell time package], [1.9.1], [ashley@semantic.org], [time])
 
 # Safety check: Ensure that we are in the correct source directory.
 AC_CONFIG_SRCDIR([lib/include/HsTime.h])
diff --git a/lib/Data/Time/Calendar/Days.hs b/lib/Data/Time/Calendar/Days.hs
--- a/lib/Data/Time/Calendar/Days.hs
+++ b/lib/Data/Time/Calendar/Days.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS -fno-warn-unused-imports #-}
-#include "HsConfigure.h"
 module Data.Time.Calendar.Days
 (
     -- * Days
@@ -9,18 +8,10 @@
 import Control.DeepSeq
 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
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-    ,Data, Typeable
-#endif
-#endif
-    )
+newtype Day = ModifiedJulianDay {toModifiedJulianDay :: Integer} deriving (Eq,Ord,Data, Typeable)
 
 instance NFData Day where
     rnf (ModifiedJulianDay a) = rnf a
diff --git a/lib/Data/Time/Clock/Internal/AbsoluteTime.hs b/lib/Data/Time/Clock/Internal/AbsoluteTime.hs
--- a/lib/Data/Time/Clock/Internal/AbsoluteTime.hs
+++ b/lib/Data/Time/Clock/Internal/AbsoluteTime.hs
@@ -1,5 +1,3 @@
--- {-# OPTIONS -fno-warn-unused-imports #-}
-#include "HsConfigure.h"
 -- | TAI and leap-second maps for converting to UTC: most people won't need this module.
 module Data.Time.Clock.Internal.AbsoluteTime
 (
@@ -9,24 +7,14 @@
 ) where
 
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Control.DeepSeq
 import Data.Time.Calendar.Days
 import Data.Time.Clock.Internal.DiffTime
 
 
 -- | AbsoluteTime is TAI, time as measured by a clock.
-newtype AbsoluteTime = MkAbsoluteTime DiffTime deriving (Eq,Ord
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
-    ,Data, Typeable
-#endif
-#endif
-#endif
-    )
+newtype AbsoluteTime = MkAbsoluteTime DiffTime deriving (Eq,Ord,Data,Typeable)
 
 instance NFData AbsoluteTime where
     rnf (MkAbsoluteTime a) = rnf a
diff --git a/lib/Data/Time/Clock/Internal/CTimeval.hs b/lib/Data/Time/Clock/Internal/CTimeval.hs
--- a/lib/Data/Time/Clock/Internal/CTimeval.hs
+++ b/lib/Data/Time/Clock/Internal/CTimeval.hs
@@ -3,7 +3,7 @@
 #ifndef mingw32_HOST_OS
 -- All Unix-specific, this
 
-#if __GLASGOW_HASKELL__ >= 709 || __GLASGOW_HASKELL__ < 702
+#if __GLASGOW_HASKELL__ >= 709
 import Foreign
 #else
 import Foreign.Safe
diff --git a/lib/Data/Time/Clock/Internal/DiffTime.hs b/lib/Data/Time/Clock/Internal/DiffTime.hs
--- a/lib/Data/Time/Clock/Internal/DiffTime.hs
+++ b/lib/Data/Time/Clock/Internal/DiffTime.hs
@@ -1,8 +1,5 @@
-#if __GLASGOW_HASKELL__ >= 702
 {-# LANGUAGE Trustworthy #-}
-#endif
 {-# OPTIONS -fno-warn-unused-imports #-}
-#include "HsConfigure.h"
 module Data.Time.Clock.Internal.DiffTime
     (
     -- * Absolute intervals
@@ -13,9 +10,7 @@
     ) where
 
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Data.Ratio ((%))
 import Data.Fixed
 import Control.DeepSeq
@@ -24,16 +19,7 @@
 -- | 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
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
-    ,Data, Typeable
-#else
-#endif
-#endif
-#endif
-    )
+newtype DiffTime = MkDiffTime Pico deriving (Eq,Ord,Data, Typeable)
 
 -- necessary because H98 doesn't have "cunning newtype" derivation
 instance NFData DiffTime where -- FIXME: Data.Fixed had no NFData instances yet at time of writing
diff --git a/lib/Data/Time/Clock/Internal/NominalDiffTime.hs b/lib/Data/Time/Clock/Internal/NominalDiffTime.hs
--- a/lib/Data/Time/Clock/Internal/NominalDiffTime.hs
+++ b/lib/Data/Time/Clock/Internal/NominalDiffTime.hs
@@ -1,18 +1,15 @@
 {-# OPTIONS -fno-warn-unused-imports #-}
-#if __GLASGOW_HASKELL__ >= 702
 {-# LANGUAGE Trustworthy #-}
-#endif
-#include "HsConfigure.h"
 module Data.Time.Clock.Internal.NominalDiffTime
     (
     NominalDiffTime,
+    secondsToNominalDiffTime,
+    nominalDiffTimeToSeconds,
     nominalDay,
     ) where
 
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Data.Fixed
 import Data.Time.Calendar.Days
 import Control.DeepSeq
@@ -24,15 +21,15 @@
 -- 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
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
-    ,Data, Typeable
-#endif
-#endif
-#endif
-    )
+newtype NominalDiffTime = MkNominalDiffTime Pico deriving (Eq,Ord,Data,Typeable)
+
+-- | Create a 'NominalDiffTime' from a number of seconds.
+secondsToNominalDiffTime :: Pico -> NominalDiffTime
+secondsToNominalDiffTime = MkNominalDiffTime
+
+-- | Get the seconds in a 'NominalDiffTime'.
+nominalDiffTimeToSeconds :: NominalDiffTime -> Pico
+nominalDiffTimeToSeconds (MkNominalDiffTime t) = t
 
 -- necessary because H98 doesn't have "cunning newtype" derivation
 instance NFData NominalDiffTime where -- FIXME: Data.Fixed had no NFData instances yet at time of writing
diff --git a/lib/Data/Time/Clock/Internal/UTCTime.hs b/lib/Data/Time/Clock/Internal/UTCTime.hs
--- a/lib/Data/Time/Clock/Internal/UTCTime.hs
+++ b/lib/Data/Time/Clock/Internal/UTCTime.hs
@@ -1,4 +1,3 @@
-#include "HsConfigure.h"
 module Data.Time.Clock.Internal.UTCTime
 (
     -- * UTC
@@ -14,9 +13,7 @@
 ) where
 
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Control.DeepSeq
 import Data.Time.Calendar.Days
 import Data.Time.Clock.Internal.DiffTime
@@ -30,14 +27,7 @@
     utctDay :: Day,
     -- | the time from midnight, 0 <= t < 86401s (because of leap-seconds)
     utctDayTime :: DiffTime
-}
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
-    deriving (Data, Typeable)
-#endif
-#endif
-#endif
+} deriving (Data, Typeable)
 
 instance NFData UTCTime where
     rnf (UTCTime d t) = rnf d `seq` rnf t `seq` ()
diff --git a/lib/Data/Time/Clock/Internal/UniversalTime.hs b/lib/Data/Time/Clock/Internal/UniversalTime.hs
--- a/lib/Data/Time/Clock/Internal/UniversalTime.hs
+++ b/lib/Data/Time/Clock/Internal/UniversalTime.hs
@@ -1,4 +1,3 @@
-#include "HsConfigure.h"
 module Data.Time.Clock.Internal.UniversalTime
     (
     -- * Universal Time
@@ -7,21 +6,13 @@
     ) where
 
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Control.DeepSeq
 
 
 -- | 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
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-    ,Data, Typeable
-#endif
-#endif
-    )
+newtype UniversalTime = ModJulianDate {getModJulianDate :: Rational} deriving (Eq,Ord,Data, Typeable)
 
 -- necessary because H98 doesn't have "cunning newtype" derivation
 instance NFData UniversalTime where
diff --git a/lib/Data/Time/Clock/TAI.hs b/lib/Data/Time/Clock/TAI.hs
--- a/lib/Data/Time/Clock/TAI.hs
+++ b/lib/Data/Time/Clock/TAI.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS -fno-warn-orphans #-}
-#include "HsConfigure.h"
 -- | TAI and leap-second maps for converting to UTC: most people won't need this module.
 module Data.Time.Clock.TAI
 (
diff --git a/lib/Data/Time/Format/Internal.hs b/lib/Data/Time/Format/Internal.hs
new file mode 100644
--- /dev/null
+++ b/lib/Data/Time/Format/Internal.hs
@@ -0,0 +1,8 @@
+{-|
+The contents of this module is liable to change, or disappear entirely.
+Please <https://github.com/haskell/time/issues/new let me know> if you depend on anything here.
+-}
+module Data.Time.Format.Internal (FormatTime(..),ParseTime(..)) where
+
+import Data.Time.Format.Format.Class
+import Data.Time.Format.Parse.Class
diff --git a/lib/Data/Time/LocalTime/Internal/LocalTime.hs b/lib/Data/Time/LocalTime/Internal/LocalTime.hs
--- a/lib/Data/Time/LocalTime/Internal/LocalTime.hs
+++ b/lib/Data/Time/LocalTime/Internal/LocalTime.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS -fno-warn-orphans #-}
-#include "HsConfigure.h"
 module Data.Time.LocalTime.Internal.LocalTime
 (
     -- * Local Time
@@ -15,9 +14,7 @@
 
 import Control.DeepSeq
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Data.Time.Calendar.Days
 import Data.Time.Calendar.Gregorian
 import Data.Time.Clock.Internal.NominalDiffTime
@@ -35,15 +32,7 @@
 data LocalTime = LocalTime {
     localDay    :: Day,
     localTimeOfDay   :: TimeOfDay
-} deriving (Eq,Ord
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
-    ,Data, Typeable
-#endif
-#endif
-#endif
-    )
+} deriving (Eq,Ord,Data, Typeable)
 
 instance NFData LocalTime where
     rnf (LocalTime d t) = rnf d `seq` rnf t `seq` ()
diff --git a/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs b/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs
--- a/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs
+++ b/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS -fno-warn-unused-imports #-}
-#include "HsConfigure.h"
 module Data.Time.LocalTime.Internal.TimeOfDay
 (
     -- * Time of day
@@ -13,9 +12,7 @@
 import Control.DeepSeq
 import Data.Typeable
 import Data.Fixed
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
 import Data.Time.Clock.Internal.DiffTime
 import Data.Time.Clock.Internal.NominalDiffTime
 import Data.Time.Calendar.Private
@@ -31,15 +28,7 @@
     -- | 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
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
-    ,Data, Typeable
-#endif
-#endif
-#endif
-    )
+} deriving (Eq,Ord,Data, Typeable)
 
 instance NFData TimeOfDay where
     rnf (TimeOfDay h m s) = rnf h `seq` rnf m `seq` s `seq` () -- FIXME: Data.Fixed had no NFData instances yet at time of writing
diff --git a/lib/Data/Time/LocalTime/Internal/TimeZone.hs b/lib/Data/Time/LocalTime/Internal/TimeZone.hs
--- a/lib/Data/Time/LocalTime/Internal/TimeZone.hs
+++ b/lib/Data/Time/LocalTime/Internal/TimeZone.hs
@@ -1,6 +1,5 @@
 {-# OPTIONS -fno-warn-unused-imports #-}
 {-# LANGUAGE ForeignFunctionInterface #-}
-#include "HsConfigure.h"
 module Data.Time.LocalTime.Internal.TimeZone
 (
     -- * Time zones
@@ -16,7 +15,7 @@
 import Data.Time.Clock.POSIX
 import Data.Time.Clock.Internal.UTCTime
 
-#if __GLASGOW_HASKELL__ >= 709 || __GLASGOW_HASKELL__ < 702
+#if __GLASGOW_HASKELL__ >= 709
 import Foreign
 #else
 import Foreign.Safe
@@ -24,9 +23,7 @@
 import Foreign.C
 import Control.DeepSeq
 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 {
@@ -36,13 +33,7 @@
     timeZoneSummerOnly :: Bool,
     -- | The name of the zone, typically a three- or four-letter acronym.
     timeZoneName :: String
-} deriving (Eq,Ord
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-    ,Data, Typeable
-#endif
-#endif
-    )
+} deriving (Eq,Ord,Data, Typeable)
 
 instance NFData TimeZone where
     rnf (TimeZone m so n) = rnf m `seq` rnf so `seq` rnf n `seq` ()
diff --git a/lib/Data/Time/LocalTime/Internal/ZonedTime.hs b/lib/Data/Time/LocalTime/Internal/ZonedTime.hs
--- a/lib/Data/Time/LocalTime/Internal/ZonedTime.hs
+++ b/lib/Data/Time/LocalTime/Internal/ZonedTime.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS -fno-warn-orphans #-}
-#include "HsConfigure.h"
 module Data.Time.LocalTime.Internal.ZonedTime
 (
     ZonedTime(..),utcToZonedTime,zonedTimeToUTC,getZonedTime,utcToLocalZonedTime
@@ -7,10 +6,7 @@
 
 import Control.DeepSeq
 import Data.Typeable
-#if LANGUAGE_Rank2Types
 import Data.Data
-#endif
-
 import Data.Time.Clock.Internal.UTCTime
 import Data.Time.Clock.POSIX
 import Data.Time.LocalTime.Internal.TimeZone
@@ -22,13 +18,7 @@
     zonedTimeToLocalTime :: LocalTime,
     zonedTimeZone :: TimeZone
 }
-#if LANGUAGE_DeriveDataTypeable
-#if LANGUAGE_Rank2Types
-#if HAS_DataPico
     deriving (Data, Typeable)
-#endif
-#endif
-#endif
 
 instance NFData ZonedTime where
     rnf (ZonedTime lt z) = rnf lt `seq` rnf z `seq` ()
diff --git a/lib/include/HsConfigure.h b/lib/include/HsConfigure.h
deleted file mode 100644
--- a/lib/include/HsConfigure.h
+++ /dev/null
@@ -1,7 +0,0 @@
-#define HAS_DataPico 0
-#if LANGUAGE_Rank2Types
-#if MIN_VERSION_base(4,2,0)
-#undef HAS_DataPico
-#define HAS_DataPico 1
-#endif
-#endif
diff --git a/time.cabal b/time.cabal
--- a/time.cabal
+++ b/time.cabal
@@ -1,5 +1,5 @@
 name:           time
-version:        1.9
+version:        1.9.1
 stability:      stable
 license:        BSD3
 license-file:   LICENSE
@@ -20,7 +20,6 @@
     aclocal.m4
     configure.ac
     configure
-    lib/include/HsConfigure.h
     lib/include/HsTime.h
     lib/include/HsTimeConfig.h.in
     test/unix/Test/Format/*.c
@@ -38,17 +37,13 @@
 library
     hs-source-dirs: lib
     default-language: Haskell2010
-    if impl(ghc)
-        default-extensions:
-            Rank2Types
-            DeriveDataTypeable
-            StandaloneDeriving
-        cpp-options: -DLANGUAGE_Rank2Types -DLANGUAGE_DeriveDataTypeable -DLANGUAGE_StandaloneDeriving
-    else
-        if impl(hugs)
-            default-extensions: Rank2Types
-            cpp-options: -DLANGUAGE_Rank2Types
+    default-extensions:
+        Rank2Types
+        DeriveDataTypeable
+        StandaloneDeriving
+        CPP
     ghc-options: -Wall -fwarn-tabs
+    c-sources: lib/cbits/HsTime.c
     build-depends:
         base >= 4.7 && < 5,
         deepseq >= 1.1
@@ -67,10 +62,9 @@
         Data.Time.Clock.TAI,
         Data.Time.LocalTime,
         Data.Time.Format,
+        Data.Time.Format.Internal,
         Data.Time.Format.ISO8601,
         Data.Time
-    default-extensions:    CPP
-    c-sources: lib/cbits/HsTime.c
     other-modules:
         Data.Format
         Data.Time.Calendar.Private,