diff --git a/Setup.hs b/Setup.hs
deleted file mode 100644
--- a/Setup.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-import Distribution.Simple
-main = defaultMain
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,10 @@
+#####   2.2.1
+   fix failing test
+
+   add toSmall conversion function
+
+   add Now instances for DatePartSmall
+
 #####   2.2.0
     add DatePartSmall
     
diff --git a/hora.cabal b/hora.cabal
--- a/hora.cabal
+++ b/hora.cabal
@@ -1,5 +1,5 @@
 name:                hora
-version:             2.2.0
+version:             2.2.1
 build-type:          Simple
 cabal-version:       >=1.10
 
@@ -10,6 +10,7 @@
 category:            System, Time
 license:             PublicDomain
 license-file:        PublicDomain
+
 extra-source-files:  changelog.md, README.md, 
                 test/TimeSeriesData/ChileContinental,
                 test/TimeSeriesData/ROC
@@ -20,7 +21,21 @@
    type: git
    location: https://github.com/ciez/hora.git
 
+flag legacy_libc
+   description: set this flag to True if you see this error message :
+         cbits-unix/init.c:3:10: error:
+         fatal error: sys/random.h: No such file or directory
+              3 | #include <sys/random.h>
+                |          ^~~~~~~~~
 
+         how to set this flag to true:
+            in cabal.project or cabal.project.local
+               add this line (0 indent):
+                   constraints: hora +legacy_libc
+   default: False
+   manual: True
+
+
 library
   exposed-modules:
           Data.Time.Hora.Span
@@ -33,16 +48,19 @@
           Data.Time.Hora.Some
 
   other-modules:
-          Data.Time.Hora.Internal.Span
           Data.Time.Hora.Internal.DatePartSmall
+          Data.Time.Hora.Internal.FromIntegral
           Data.Time.Hora.Internal.Pad
+          Data.Time.Hora.Internal.Span
+
   ghc-options:  -fwarn-unused-imports
-    
+
   build-depends:       base >=4.7 && <5.0,
                        time,
                        timezone-series,
                        binary
-                       
+
+
   hs-source-dirs:      src
   default-language:    Haskell2010
   default-extensions:   FlexibleInstances
@@ -63,7 +81,7 @@
 
 
 test-suite spec
-  default-language:Haskell2010
+  default-language:     Haskell2010
   type: exitcode-stdio-1.0
   ghc-options:  -fwarn-unused-imports
   hs-source-dirs: test, src
@@ -87,36 +105,39 @@
   other-modules:
            Data.Time.Hora.Format
            Data.Time.Hora.Future
+           Data.Time.Hora.Internal.DatePartSmall
+           Data.Time.Hora.Internal.FromIntegral
+           Data.Time.Hora.Internal.Pad
+           Data.Time.Hora.Internal.Span
            Data.Time.Hora.Part
            Data.Time.Hora.Some
            Data.Time.Hora.Span
            Data.Time.Hora.Stamp
            Data.Time.Hora.Type
            Data.Time.Hora.Zone
+           Test.TestAncientDate
+           Test.TestCheckOverflow
            Test.TestConvert
+           Test.TestDatePart
+           Test.TestDatePartSmall
+           Test.TestDatePartSmallConvert
+           Test.TestDatePartSmallDoc
            Test.TestDiffTime
-           Test.TestFuture
-           Test.TestTime
            Test.TestDmyHm
+           Test.TestFormat
+           Test.TestFuture
            Test.TestPico
            Test.TestPico2
-           Test.TestDatePart
-           Test.TestUtc
-           Test.TestZone
+           Test.TestRoundtripPicoMilli
            Test.TestSome
-           Test.TestFormat
-           Test.TestUTCTimeBin
-           Test.TestAncientDate
-           Test.TestDatePartSmall
+           Test.TestStamp
            Test.TestStorageSize
-           Test.TestDatePartSmallConvert
-           Test.TestRoundtripPicoMilli
-           Test.TestDatePartSmallDoc
-           Data.Time.Hora.Internal.Span
-           Data.Time.Hora.Internal.DatePartSmall
-           Test.TestCheckOverflow
-           Data.Time.Hora.Internal.Pad
-  build-depends:  base >= 4.8,
+           Test.TestTime
+           Test.TestUTCTimeBin
+           Test.TestUtc
+           Test.TestZone
+
+  build-depends:  base >=4.7 && <5.0,
                   hspec >= 2.1.7,
                   QuickCheck >= 2.8.1,
                   time,
@@ -124,3 +145,6 @@
                   timezone-olson,
                   binary,
                   bytestring
+
+  if flag(legacy_libc)
+      build-depends: splitmix <= 0.1.1.0
diff --git a/src/Data/Time/Hora/Format.hs b/src/Data/Time/Hora/Format.hs
--- a/src/Data/Time/Hora/Format.hs
+++ b/src/Data/Time/Hora/Format.hs
@@ -1,10 +1,12 @@
-module Data.Time.Hora.Format 
+-- | 'Format' enum
+module Data.Time.Hora.Format
     (-- * type
     Format(..),
     -- * format
     format,
     format',
-    show') where
+    show'
+    ) where
 
 import Data.Maybe
 import Data.String
@@ -23,14 +25,14 @@
 
 
 -- | format as local time in specified timezone
-format'::Tz' tz =>
+format' :: Tz' tz =>
     [Format] -> tz -> UTCTime -> Tz String
 format' lf0 tz0 utc0 = Tz tz1 $ withDefaultLocale (build lf0) zt1
-        where zt1 = utcToZonedTime tz1 utc0::ZonedTime
+        where zt1 = utcToZonedTime tz1 utc0 :: ZonedTime
               tz1 = tz' tz0 utc0
 
 
-withDefaultLocale::FormatTime t =>
+withDefaultLocale :: FormatTime t =>
         String  -- ^ format. see 'formatTime' 
         -> t
         -> String
@@ -79,11 +81,9 @@
     | Wk_year_Mon -- ^ week of year start Monday
 
 
-
-
 {-| build format string from 'Format' -}
 class Build f where
-    build::f -> String
+    build :: f -> String
 
 
 instance Build [Format] where
@@ -156,7 +156,7 @@
 >>> show' $ T.negate $ toSpan $ mkMin 14 53
     -14:53
 -}
-show'::DatePartSmall -> String
+show' :: DatePartSmall -> String
 show' dp0
    | (Day d0) <- dp0
          = format [Y_m_d] $ fromJust $ toUtc $ DatePartSmall d0 0 0
diff --git a/src/Data/Time/Hora/Future.hs b/src/Data/Time/Hora/Future.hs
--- a/src/Data/Time/Hora/Future.hs
+++ b/src/Data/Time/Hora/Future.hs
@@ -1,7 +1,9 @@
+-- | 'C.UTCTime' 'TimeSpan' from now
+-- | 'PicoDiff' : difference between times
 module Data.Time.Hora.Future where
 
 import Data.Fixed
-import Data.Time.Clock
+import Data.Time.Clock as C
 import Data.Time.Hora.Span
 import Data.Time.Hora.Type
 import Prelude as P
@@ -29,7 +31,7 @@
     
 return TimeSpan for ease of conversion with "Data.Time.Hora.Span"    -}
 class PicoDiff a where
-    (-)::a -> a -> TimeSpan Integer
+    (-) :: a -> a -> TimeSpan Integer
 
 
 instance PicoDiff UTCTime where
diff --git a/src/Data/Time/Hora/Internal/DatePartSmall.hs b/src/Data/Time/Hora/Internal/DatePartSmall.hs
--- a/src/Data/Time/Hora/Internal/DatePartSmall.hs
+++ b/src/Data/Time/Hora/Internal/DatePartSmall.hs
@@ -1,10 +1,13 @@
+{- | 'DatePartSmall' uses fixed-size storage -}
 module Data.Time.Hora.Internal.DatePartSmall where
 
-import Data.Binary
-import Data.Time.Hora.Internal.Span
-import GHC.Generics
 import Prelude hiding (negate)
+import GHC.Generics
 
+import Data.Binary
+import Data.Time.Hora.Internal.FromIntegral (fi)
+
+
 {- |  'DatePartSmall' uses fixed-size storage. Storage (as encoded with "Data.Binary".encode) varies with the constructor used, is noted as \".. bytes\" against each constructor.
 
       allows to operate with dates only ..
@@ -17,9 +20,9 @@
 
       max date is: 11759222-01-19. That's 19 Jan 11759222
 
-      see "Data.Time.Hora.Part" for conversion between 'UTCTime' and 'DatePartSmall'
+      see "Data.Time.Hora.Part" for conversion between 'Data.Time.Clock.UTCTime' and 'DatePartSmall'
 
-      only values constructed with 'DatePartSmall' can be converted to 'UTCTime'
+      only values constructed with 'DatePartSmall' can be converted to 'Data.Time.Clock.UTCTime'
   -}
 data DatePartSmall = Day Word32  {- ^ days after 31 Dec 1 BC: 1 Jan AD 1 is day 1. See https://en.wikipedia.org/wiki/Anno_Domini
 
@@ -65,7 +68,7 @@
 
    'Ms' -> 'Ms''
 -}
-toSpan::DatePartSmall -> DatePartSmall
+toSpan :: DatePartSmall -> DatePartSmall
 toSpan dp0 = case dp0 of
                Day d1 -> Day' d1
                Min m1 -> Min' m1
@@ -74,7 +77,7 @@
 
 {- | adds hidden Neg constructor to 'Day'', 'Min'' or 'Ms''
 to enable negative spans   -}
-negate::DatePartSmall -> DatePartSmall
+negate :: DatePartSmall -> DatePartSmall
 negate dp0 = case dp0 of
                Neg dp1 -> dp1
                Day' d1 -> Neg dp0
@@ -83,11 +86,12 @@
                otherwise -> dp0
 
 -- | checks if 'DatePartSmall' is a negative span
-isNegative::DatePartSmall -> Bool
+isNegative :: DatePartSmall -> Bool
 isNegative dp0 = case dp0 of
                      (Neg _) -> True
                      otherwise -> False
 
+-- | error detail enum
 data ErrorDetail = Invalid    -- ^ operation is not possible with these constructors
                 | Overflow    -- ^ data type maxed out
                 | Invalid_Overflow  -- ^ 'Invalid' <> 'Overflow'
@@ -175,12 +179,12 @@
 
 when incrementing and decrementing, overflow is checked on both upper (max for Word16, Word32) and lower (0) bounds
 
-when incrementing, it is possible to normalize time by recalculating minutes from seconds, days from minutes. See 'normalize' in "Data.Time.Hora.Part"
+when incrementing, it is possible to normalize time by recalculating minutes from seconds, days from minutes. See 'Data.Time.Hora.Part.normalize' in "Data.Time.Hora.Part"
 
 when decrementing, normalization is not yet implemented. todo
 -}
 
-incrDecr::(Int -> Int -> Int)  -- ^ op (+) (-)
+incrDecr :: (Int -> Int -> Int)  -- ^ op (+) (-)
                      -> DatePartSmall
                      -> DatePartSmall
                      -> DatePartSmall
@@ -235,9 +239,7 @@
                   | otherwise = Error Invalid
 
 
-
-
-checkOverflow::forall a b. (Bounded a, Integral a, Num a) =>
+checkOverflow :: forall a b. (Bounded a, Integral a, Num a) =>
    (a -> DatePartSmall)    -- ^ ctor
    -> a
    -> (Int -> Int -> Int)  -- ^ op (+) (-)
@@ -248,10 +250,10 @@
                && result1 <= max_aInt1
                then ctor0 $ fi result1
                else Error Overflow
-   where b1 = fi a1::Int
-         b2 = fi a2::Int
-         min_a1 = minBound::a
-         min_aInt1 = fi min_a1::Int
-         max_a1 = maxBound::a
-         max_aInt1 = fi max_a1::Int
-         result1 = op0 b1 b2::Int
+   where b1 = fi a1 :: Int
+         b2 = fi a2 :: Int
+         min_a1 = minBound :: a
+         min_aInt1 = fi min_a1 :: Int
+         max_a1 = maxBound :: a
+         max_aInt1 = fi max_a1 :: Int
+         result1 = op0 b1 b2 :: Int
diff --git a/src/Data/Time/Hora/Internal/FromIntegral.hs b/src/Data/Time/Hora/Internal/FromIntegral.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Time/Hora/Internal/FromIntegral.hs
@@ -0,0 +1,7 @@
+module Data.Time.Hora.Internal.FromIntegral where
+
+-- | constraint
+type TwoInt a b = (Integral a, Integral b)
+
+fi :: TwoInt a b => a -> b
+fi = fromIntegral
diff --git a/src/Data/Time/Hora/Internal/Pad.hs b/src/Data/Time/Hora/Internal/Pad.hs
--- a/src/Data/Time/Hora/Internal/Pad.hs
+++ b/src/Data/Time/Hora/Internal/Pad.hs
@@ -10,7 +10,7 @@
 
  "--abc"    -}
 
-pad::Char -> Int -> String -> String
+pad :: Char -> Int -> String -> String
 pad c0 tot0 txt0 = p1 ++ txt0
     where p1 = pad_ c0 tot0 txt0
 
@@ -20,10 +20,10 @@
     >>> pad' '-' 5 "abc"
 
      "abc--"        -}
-pad'::Char -> Int -> String -> String
+pad' :: Char -> Int -> String -> String
 pad' c0 tot0 txt0 = txt0 ++ p1
     where p1 = pad_ c0 tot0 txt0
 
 
-pad_::Char -> Int -> String -> String
+pad_ :: Char -> Int -> String -> String
 pad_ c0 tot0 txt0 = [const c0 p1 | p1 <- [1..(tot0 - (length txt0))]]
diff --git a/src/Data/Time/Hora/Internal/Span.hs b/src/Data/Time/Hora/Internal/Span.hs
--- a/src/Data/Time/Hora/Internal/Span.hs
+++ b/src/Data/Time/Hora/Internal/Span.hs
@@ -1,5 +1,7 @@
 module Data.Time.Hora.Internal.Span where
 
+import Data.Time.Hora.Internal.FromIntegral as F (fi, TwoInt)
+
 {- | second and fractions
 
 see "Data.Time.Hora.Span" for conversion    -}
@@ -7,13 +9,8 @@
                 | Pico a
                 | Milli a deriving (Show, Functor)
 
--- | constraint
-type TwoInt a b = (Integral a, Integral b)
 
-fi::TwoInt a b => a -> b
-fi = fromIntegral
-
-withPico::Integral a => (a -> a -> a) ->
+withPico :: Integral a => (a -> a -> a) ->
     TimeSpan a -> TimeSpan a -> TimeSpan a
 withPico fn0 a0 b0 = Pico $ fn0 a1 b1
         where a1 = toPico a0
@@ -22,38 +19,38 @@
 
 {- | >>> toPico (Milli 1)
 1000000000 -}
-toPico::TwoInt a b => TimeSpan a -> b
-toPico (Pico i0) = fromIntegral i0
-toPico (Milli i0) = fromIntegral $ i0 * picoMs
-toPico (Sec i0) = fromIntegral $ i0 * picoSec
+toPico :: TwoInt a b => TimeSpan a -> b
+toPico (Pico i0) = fi i0
+toPico (Milli i0) = fi $ i0 * picoMs
+toPico (Sec i0) = fi $ i0 * picoSec
 
 
 
 {- | >>> toMilli $ Sec 5
 5000   -}
-toMilli::TwoInt a b => TimeSpan a -> b
-toMilli (Pico i0) = fromIntegral $ i0 `div` picoMs
-toMilli (Milli i0) = fromIntegral $ i0
-toMilli (Sec i0) = fromIntegral $ i0 * msSec
+toMilli :: TwoInt a b => TimeSpan a -> b
+toMilli (Pico i0) = fi $ i0 `div` picoMs
+toMilli (Milli i0) = fi $ i0
+toMilli (Sec i0) = fi $ i0 * msSec
 
 
 {- | >>> toSec $ Milli 781200
 781     -}
-toSec::TwoInt a b => TimeSpan a -> b
-toSec (Pico i0) = fromIntegral $ i0 `div` picoSec
-toSec (Milli i0) = fromIntegral $ i0 `div` msSec
-toSec (Sec i0) = fromIntegral $ i0
+toSec :: TwoInt a b => TimeSpan a -> b
+toSec (Pico i0) = fi $ i0 `div` picoSec
+toSec (Milli i0) = fi $ i0 `div` msSec
+toSec (Sec i0) = fi $ i0
 
 
 -- | pico in 1 second
-picoSec::Integral a => a
+picoSec :: Integral a => a
 picoSec = 1000000000000     --  12
 
 -- | pico in 1 milli
-picoMs::Integral a => a
+picoMs :: Integral a => a
 picoMs = 1000000000         --  9
 
 
 -- | milli in 1 sec
-msSec::Integral a => a
+msSec :: Integral a => a
 msSec = 1000
diff --git a/src/Data/Time/Hora/Part.hs b/src/Data/Time/Hora/Part.hs
--- a/src/Data/Time/Hora/Part.hs
+++ b/src/Data/Time/Hora/Part.hs
@@ -1,4 +1,4 @@
--- | convert  between 'UTCTime', 'UTCTimeBin', 'DatePart', 'DatePartSmall'
+-- | convert  between 'C.UTCTime', 'UTCTimeBin', 'DatePart', 'DatePartSmall'
 module Data.Time.Hora.Part 
         (-- * FromUTC
         FromUTC(..),
@@ -9,29 +9,36 @@
         mkDay,
         mkMin,
         mkMs,
+        toSmall,
         normalize,
         julian_day_offset
          ) where
 
 import Data.Fixed
 import Data.Ratio
-import Data.Time.Calendar
-import Data.Time.Clock
-import Data.Time.Hora.Internal.Span
+import Data.Word
+import Data.Time.Calendar as C
+import Data.Time.Clock as C
+
+import Data.Time.Hora.Internal.DatePartSmall as S
+import Data.Time.Hora.Internal.Span as S
 import Data.Time.Hora.Span
-import Data.Time.Hora.Type
+import Data.Time.Hora.Type as T
 import Data.Time.LocalTime as L
-import Data.Word
+import Data.Time.Hora.Internal.FromIntegral (fi)
 
+
+-- | convert 'C.UTCTime' to implemented types
 class FromUTC a where
-     fromUtc::UTCTime -> a
+     fromUtc :: UTCTime -> a
 
+
 -- | returns DatePart a in UTC timezone
 instance Integral a => FromUTC (DatePart a) where
-   fromUtc::Integral a => UTCTime -> DatePart a
+   fromUtc :: Integral a => UTCTime -> DatePart a
    fromUtc t0 =
-       let day1 = utctDay t0::Day
-           dt1 = utctDayTime t0::DiffTime
+       let day1 = utctDay t0 :: Day
+           dt1 = utctDayTime t0 :: DiffTime
            (y1,m1,d1) = toGregorian day1
            (tod1, sec5, pico5) = todSecPico dt1
        in DatePart {
@@ -45,16 +52,16 @@
                }
 
 
--- | extract (TimeIfDay, seconds, picoseconds) from 'DiffTime'
-todSecPico::Integral a => DiffTime -> (TimeOfDay, a, Integer)
+-- | extract ('TimeOfDay', seconds, picoseconds) from 'DiffTime'
+todSecPico :: Integral a => DiffTime -> (TimeOfDay, a, Integer)
 todSecPico dt0 = (tod1, sec5, pico5)
-   where tod1 = timeToTimeOfDay dt0::TimeOfDay
-         pico4 = todSec tod1::Fixed E12
+   where tod1 = timeToTimeOfDay dt0 :: TimeOfDay
+         pico4 = todSec tod1 :: Fixed E12
          (sec5, MkFixed pico5) = properFraction pico4
 
 
-diffTime::Int        -- ^ hour
-        -> Int       -- ^ minute
+diffTime :: Int        -- ^ hour
+        -> Int         -- ^ minute
         -> Fixed E12   -- ^ pico
         -> DiffTime
 diffTime h0 m0 p0 = timeOfDayToTime tod1
@@ -62,23 +69,22 @@
 
 
 instance FromUTC UTCTimeBin where
-      fromUtc::UTCTime -> UTCTimeBin
+      fromUtc :: UTCTime -> UTCTimeBin
       fromUtc t0 = UTCTimeBin day1 pico1
             where day1 = toModifiedJulianDay $ utctDay t0
-                  pico1 =  diffTimeToPicoseconds $ utctDayTime t0
+                  pico1 = diffTimeToPicoseconds $ utctDayTime t0
 
 
 instance FromUTC DatePartSmall where
-      fromUtc::UTCTime -> DatePartSmall
+      fromUtc :: UTCTime -> DatePartSmall
       fromUtc t0 = DatePartSmall day2 minute2 milli2
-            where dp1 = fromUtc t0::DatePart Int
-                  UTCTimeBin julian1 _ = fromUtc t0::UTCTimeBin
+            where dp1 = fromUtc t0 :: DatePart Int
+                  UTCTimeBin julian1 _ = fromUtc t0 :: UTCTimeBin
                   day2 = fi julian1 + julian_day_offset
                   minute2 = fi $ hour dp1 * 60 + minute dp1
                   milli2 = fromSec3 + fromPico3
-                  fromSec3 = toMilli (Sec $ second dp1)::Word32
-                  fromPico3 = toMilli $ Pico $ pico dp1::Word32
-
+                  fromSec3 = toMilli (Sec $ second dp1) :: Word32
+                  fromPico3 = toMilli $ Pico $ pico dp1 :: Word32
 
 
 
@@ -87,7 +93,7 @@
 Tz (DatePart a)  parts show local date & time  
 
 see also "Data.Time.Hora.Zone"  -}
-fromUtc'::(Tz' tz, Integral a) => 
+fromUtc' :: (Tz' tz, Integral a) =>
     tz -> UTCTime -> Tz (DatePart a)
 fromUtc' tz0 utc0 =
     let tz1 = tz' tz0 utc0 
@@ -104,16 +110,16 @@
                      second = fi sec5,
                      pico = fi pico5
                    }
-        pico4 = todSec time2::Fixed E12
+        pico4 = todSec time2 :: Fixed E12
         (sec5, MkFixed pico5) = properFraction pico4
     in Tz tz1 d4        
 
 
-{-| convert 'DatePart' -> 'UTCTime'
+{-| convert 'DatePart' -> 'C.UTCTime'
 
 Invalid date returns Nothing -}
 class ToUTC a where
-    toUtc::a -> Maybe UTCTime
+    toUtc :: a -> Maybe UTCTime
 
 
 instance Integral a => ToUTC (DatePart a) where
@@ -122,7 +128,7 @@
             min1 = minute dp0 * 60  --  as second
             s2 = second dp0 + h1 + min1
             diff1 = secondsToDiffTime $ fi s2
-            diff2 = picosecondsToDiffTime $ fi $ pico dp0          
+            diff2 = picosecondsToDiffTime $ fi $ pico dp0
             
             mday1 = fromGregorianValid (fi $ year dp0)
                             (fi $ month dp0) $ fi $ day dp0
@@ -133,11 +139,16 @@
 instance Integral a => ToUTC (Tz (DatePart a)) where
     toUtc (Tz tz0 dp0) =
         let s1 = toPico $ Sec $ second dp0
-            mtod1 = makeTimeOfDayValid (fi $ hour dp0) 
-                                        (fi $ minute dp0) 
-                                        (timeSpanPico $ Pico s1 + (Pico $ fi $ pico dp0)) 
-            mday1 = fromGregorianValid (fi $ year dp0)
-                            (fi $ month dp0) $ fi $ day dp0
+            mtod1 = makeTimeOfDayValid (fi $ hour dp0)
+                                        (fi $ minute dp0)
+                                        (timeSpanPico $
+                                             Pico s1 +
+                                             (Pico $ fi $ pico dp0)
+                                          )
+            mday1 :: Maybe C.Day = fromGregorianValid
+                                        (fi $ year dp0)
+                                        (fi $ month dp0)
+                                        (fi $ day dp0)
         in mday1 >>= \day1 ->
             mtod1 >>= \tod1 ->
                 let lt1 = LocalTime day1 tod1
@@ -155,16 +166,19 @@
    toUtc dp0@(DatePartSmall _ _ _) = Just utc1
         where (DatePartSmall d0 m0 ms0) = normalize dp0
               utc1 = UTCTime day2 diff2
-              day1 = fi d0 - julian_day_offset::Integer
+
               day2 = ModifiedJulianDay day1
+                  where day1 = fi d0 - julian_day_offset :: Integer
+
               diff2 = diffTime hr1 min1 pico2
-              min1 = fi $ m0 `rem` 60
-              hr1 = fi $ m0 `div` 60
-              sec1 = fi $ ms0 `div` 1000
-              sec2 = MkFixed $ sec1 * picoSec::Fixed E12
-              ms1 = fi ms0::Integer
-              pico1 = fromRational $ (ms1 `rem` 1000) % 1000::Fixed E12
-              pico2 = sec2 + pico1
+                  where min1 = fi $ m0 `rem` 60
+                        hr1 = fi $ m0 `div` 60
+                        pico2 = sec2 + pico1
+                           where sec2 = MkFixed $ sec1 * picoSec :: Fixed E12
+                                 pico1 = fromRational $ (ms1 `rem` 1000) % 1000 :: Fixed E12
+                                 ms1 = fi ms0 :: Integer
+                                 sec1 = fi $ ms0 `div` 1000
+
    toUtc _ = Nothing
 
 
@@ -176,41 +190,52 @@
 
 >>> mkDay 1858 11 17 `shouldBe` (Day julian_day_offset)
 -}
-julian_day_offset::Integral a => a
-julian_day_offset = fromIntegral 678576
+julian_day_offset :: Integral a => a
+julian_day_offset = fi 678576
 
 
+-- | convert 'DatePart' to 'DatePartSmall' with some loss of precision
+toSmall :: Integral a =>
+      DatePart a -> DatePartSmall
+toSmall DatePart{..} =
+   let S.Day d = mkDay year month day
+       S.Min m = mkMin hour minute
+       S.Ms ms = mkMs second $ toMilli $ Pico pico
+   in DatePartSmall d m ms
+
+
 -- | day / date
-mkDay::Integral a =>
+mkDay :: Integral a =>
          a     -- ^ year
         -> a   -- ^ month
         -> a   -- ^ day
-        -> DatePartSmall   -- ^ 'Day'
+        -> DatePartSmall   -- ^ 'T.Day'
 mkDay y0 m0 d0 = maybe (Error Invalid) id mday2
-   where mday2 = valid2 <$> mday1::Maybe DatePartSmall
-         mday1 = fromGregorianValid y1 m1 d1
-         valid2 = Day . fromIntegral . (+ julian_day_offset) . toModifiedJulianDay
-         y1 = fromIntegral y0
-         m1 = fromIntegral m0
-         d1 = fromIntegral d0
+   where mday2 = valid2 <$> mday1 :: Maybe DatePartSmall
+         mday1 :: Maybe C.Day = fromGregorianValid y1 m1 d1
+         valid2 = T.Day . fi . (+ julian_day_offset) . toModifiedJulianDay
+         y1 = fi y0
+         m1 = fi m0
+         d1 = fi d0
 
 
 -- | minutes including hours
-mkMin::(Num a, Integral a) =>
+mkMin :: (Num a, Integral a) =>
         a      -- ^ hour
         -> a   -- ^ minute
         -> DatePartSmall   -- ^ 'Min'
-mkMin h0 m0 = Min $ fromIntegral $ h0 * 60 + m0
+mkMin h0 m0 = Min $ fi $ h0 * 60 + m0
 
 
 -- | milliseconds including seconds
-mkMs::(Num a, Integral a) =>
+mkMs :: (Num a, Integral a) =>
         a      -- ^ second
         -> a   -- ^ millisecond
         -> DatePartSmall   -- ^ 'Ms'
-mkMs s0 ms0 = Ms $ fromIntegral $ toMilli (Sec s0) + ms0
+mkMs s0 ms0 = Ms $ fi $ toMilli (Sec s0) + ms0
 
 
+
 {- |  for ('Time', 'DatePartSmall') increase:
 
       minutes if seconds > 60
@@ -221,10 +246,10 @@
 
       this function is called by 'toUtc' before the conversion
 -}
-normalize::DatePartSmall -> DatePartSmall
+normalize :: DatePartSmall -> DatePartSmall
 normalize dp0
    | (Time m1 ms1) <- dp0,
-         ms2::Int <- fi ms1,
+         ms2 :: Int <- fi ms1,
          sec1 <- ts ms2,
          sec1 >= 60
             = let m3 = (sec1 `div` 60) + (fi m1::Int)
@@ -233,7 +258,7 @@
               in Time (fi m3) $ fi ms3
 
    | (DatePartSmall d1 m1 ms1) <- dp0,
-         ms2::Int <- fi ms1,
+         ms2 :: Int <- fi ms1,
          sec1 <- ts ms2,
          sec1 >= 60
             = let Time m2 ms2 = normalize $ Time m1 ms1
@@ -249,9 +274,8 @@
               in DatePartSmall (fi d2) (fi m3) ms1
 
    | otherwise = dp0
-
-tm::Integral a => a -> a
-tm = toMilli . Sec
+   where ts :: Integral a => a -> a
+         ts = toSec . Milli
 
-ts::Integral a => a -> a
-ts = toSec . Milli
+         tm :: Integral a => a -> a
+         tm = toMilli . Sec
diff --git a/src/Data/Time/Hora/Span.hs b/src/Data/Time/Hora/Span.hs
--- a/src/Data/Time/Hora/Span.hs
+++ b/src/Data/Time/Hora/Span.hs
@@ -1,4 +1,5 @@
-module Data.Time.Hora.Span 
+{- | Conversion between 'TimeSpan', 'DiffTime', 'NominalDiffTime', 'F.pico' -}
+module Data.Time.Hora.Span
     (-- ** 'TimeSpan'
     toPico,
     toMilli,
@@ -7,7 +8,7 @@
     picoSec,
     picoMs,
     msSec,
-    -- ** 'Pico' - 'TimeSpan' conversion
+    -- ** 'F.Pico' - 'TimeSpan' conversion
     picoTimeSpan,
     timeSpanPico,
     -- ** diff time
@@ -15,28 +16,34 @@
     nominalDiff
     ) where
 
-import Data.Fixed
+import Data.Fixed as F
 import Data.Ratio
 import Data.Time.Clock
 import Data.Time.Hora.Type
-import Data.Time.Hora.Internal.Span
+import Data.Time.Hora.Internal.Span as S
+import Data.Time.Hora.Internal.FromIntegral (fi)
 
 
-toDiffTime::Integral a => TimeSpan a -> DiffTime
-toDiffTime (Sec s0) = secondsToDiffTime $ fromIntegral s0
-toDiffTime (Pico s0) = picosecondsToDiffTime $ fromIntegral s0
+
+-- | convert 'TimeSpan' to 'DiffTime'
+toDiffTime :: Integral a => TimeSpan a -> DiffTime
+toDiffTime (Sec s0) = secondsToDiffTime $ fi s0
+toDiffTime (S.Pico s0) = picosecondsToDiffTime $ fi s0
 toDiffTime t0@(Milli s0) = picosecondsToDiffTime $ toPico t0
 
 
-nominalDiff::Integral a => TimeSpan a -> NominalDiffTime
+-- | convert 'TimeSpan' to 'NominalDiffTime'
+nominalDiff :: Integral a => TimeSpan a -> NominalDiffTime
 nominalDiff ts0 = let s1 = toPico ts0::Integer
                 in fromRational $ s1 % picoSec
 
 
-picoTimeSpan::Integral a => Pico -> TimeSpan a
-picoTimeSpan (MkFixed p0) = Pico $ fromIntegral p0
+-- | convert 'F.Pico' to 'TimeSpan'
+picoTimeSpan :: Integral a => F.Pico -> TimeSpan a
+picoTimeSpan (MkFixed p0) = S.Pico $ fi p0
 
 
-timeSpanPico::Integral a => TimeSpan a -> Pico 
-timeSpanPico ts0 = MkFixed $ fromIntegral p0
+-- | convert 'TimeSpan' to 'F.Pico'
+timeSpanPico :: Integral a => TimeSpan a -> F.Pico
+timeSpanPico ts0 = MkFixed $ fi p0
         where p0 = toPico ts0
diff --git a/src/Data/Time/Hora/Stamp.hs b/src/Data/Time/Hora/Stamp.hs
--- a/src/Data/Time/Hora/Stamp.hs
+++ b/src/Data/Time/Hora/Stamp.hs
@@ -1,4 +1,5 @@
-module Data.Time.Hora.Stamp 
+-- |
+module Data.Time.Hora.Stamp
     (-- * numerical
     Now(..),
     -- * 'String'
@@ -7,59 +8,63 @@
 
 import Data.Time.Clock
 import Data.Time.Hora.Format
-import Data.Time.Hora.Part
+import Data.Time.Hora.Part as P
 import Data.Time.Hora.Type
 import Data.Time.LocalTime as L
 
 
 -- | numeric 
 class Now a where
-    now::IO a
+    now :: IO a
 
 instance Integral a => Now (DatePart a) where
     now = withUTCTime fromUtc
 {-^ UTC 
 
->>> now::IO(DatePart Int)
+>>> now :: IO (DatePart Int)
 DatePart {year = 2016, month = 12, day = 15, hour = 10, minute = 20, second = 31, pico = 494880242000}
 -}
 
+instance Now DatePartSmall where
+    now = withUTCTime fromUtc
+{-^ UTC -}
 
+
 instance Now UTCTime where
     now = getCurrentTime
-{- ^ >>> now::IO UTCTime
+{-^ >>> now :: IO UTCTime
 2016-12-15 10:20:54.664155598 UTC       -}
 
 
 instance Integral a => Now (Tz (DatePart a)) where
     now = withTimeZone fromUtc'
-{- ^ local timezone 
+{-^ local timezone
 
 'Tz' ('DatePart' a)  parts show local date & time
 
->>> now::IO(Tz (DatePart Int))
+>>> now :: IO(Tz (DatePart Int))
 Tz CET (DatePart {year = 2016, month = 12, day = 15, hour = 11, minute = 21, second = 21, pico = 657029375000})     -}
 
 
+instance Now (Tz DatePartSmall) where
+    now = withTimeZone fromUtc' >>=
+         \tsdp -> pure $ P.toSmall <$> tsdp
+{-^ local timezone -}
 
-withTimeZone::(TimeZone -> UTCTime -> Tz a) -> IO (Tz a)
-withTimeZone fn0 = do
-    z1 <- getCurrentTimeZone    --  CET | CEST
-    t1 <- getCurrentTime
-    pure $ fn0 z1 t1
 
+withTimeZone :: (TimeZone -> UTCTime -> Tz a) -> IO (Tz a)
+withTimeZone fn0 = fn0 <$> getCurrentTimeZone <*> getCurrentTime
 
-withUTCTime::(UTCTime -> a) -> IO a
-withUTCTime fn0 = do
-    t1 <- getCurrentTime
-    pure $ fn0 t1
 
+withUTCTime :: (UTCTime -> a) -> IO a
+withUTCTime fn0 = fn0 <$> getCurrentTime
 
+
 {- | timestamp in specified format
 
 see "Data.Time.Hora.Some" for common ['Format']s      -}
 class Timestamp out where
-    ts::[Format] -> IO out
+    ts :: [Format] -> IO out
     
     
 instance Timestamp String where
@@ -71,6 +76,6 @@
 -- ^ local timezone
 
 
--- | timestamp in specified format, 'TimeZone' | 'TimeZoneSeries'
-ts'::Tz' tz => [Format] -> tz -> IO (Tz String)
+-- | timestamp in specified format, 'L.TimeZone' | 'Data.Time.LocalTime.TimeZone.Series.TimeZoneSeries'
+ts' :: Tz' tz => [Format] -> tz -> IO (Tz String)
 ts' lf0 tz0 = withUTCTime $ format' lf0 tz0 
diff --git a/src/Data/Time/Hora/Type.hs b/src/Data/Time/Hora/Type.hs
--- a/src/Data/Time/Hora/Type.hs
+++ b/src/Data/Time/Hora/Type.hs
@@ -1,4 +1,5 @@
-module Data.Time.Hora.Type 
+{- | 'DatePart', 'DatePartSmall', 'UTCTimeBin', 'Tz', 'TimeSpan'  -}
+module Data.Time.Hora.Type
     (-- * DatePart
     DatePart(..),
     -- * DatePartSmall
@@ -14,23 +15,24 @@
     Tz'(..),
     -- * TimeSpan 
     TimeSpan(..),
-    TwoInt(..)) where
+    TwoInt) where
 
 import Data.Binary
-import Data.Time.Clock
+import Data.Time.Clock as C
 import Data.Time.Hora.Internal.DatePartSmall
+import Data.Time.Hora.Internal.FromIntegral
 import Data.Time.Hora.Internal.Span
-import Data.Time.LocalTime
-import Data.Time.LocalTime.TimeZone.Series
+import Data.Time.LocalTime as L
+import Data.Time.LocalTime.TimeZone.Series as S
 import GHC.Generics
 import Prelude hiding (negate)
 
 
 {- | serializeable structure for essential Date, Time parts
 
-may also be used to construct 'UTCTime'     
+may also be used to construct 'C.UTCTime'
 
-see "Data.Time.Hora.Part" for conversion between 'UTCTime' and 'DatePart'   -}
+see "Data.Time.Hora.Part" for conversion between 'C.UTCTime' and 'DatePart'   -}
 data DatePart a = DatePart {
     year::a,
     month::a,
@@ -90,11 +92,11 @@
 -- private
 data Ord_ = Stop Bool | Continue
 
-{- | 'UTCTimeBin' closely mimicks 'UTCTime' without loss of precision
+{- | 'UTCTimeBin' closely mimicks 'C.UTCTime' without loss of precision
 
-'UTCTimeBin' has 'Binary' instance. The only purpose of 'UTCTimeBin' is to offer faster conversion from / to 'UTCTime' and more compact  serialization compared with 'DatePart'.
+'UTCTimeBin' has 'Binary' instance. The only purpose of 'UTCTimeBin' is to offer faster conversion from / to 'C.UTCTime' and more compact  serialization compared with 'DatePart'.
 
-see "Data.Time.Hora.Part" for conversion between 'UTCTime' and 'UTCTimeBin'      -}
+see "Data.Time.Hora.Part" for conversion between 'C.UTCTime' and 'UTCTimeBin'      -}
 data UTCTimeBin = UTCTimeBin {
             modifiedJulianDay::Integer,    -- ^ The Modified Julian Day is a standard count of days, with zero being the day 1858-11-17
             diffTimeAsPicoseconds::Integer   -- ^ 'DiffTime' expressed as picoseconds
@@ -114,18 +116,18 @@
 deriving instance Ord a => Ord (Tz a) 
 
 
--- | 'TimeZone' | 'TimeZoneSeries'
+-- | 'L.TimeZone' | 'S.TimeZoneSeries'
 class Tz' tz where
-    tz'::tz -> UTCTime -> TimeZone
+    tz' :: tz -> C.UTCTime -> TimeZone
 
 instance Tz' TimeZone where
     tz' tz0 _ = tz0
 
 instance Tz' TimeZoneSeries where
     tz' = timeZoneFromSeries
-{- ^ see "Data.Time.Hora.Zone" re: 'TimeZoneSeries'
+{- ^ see "Data.Time.Hora.Zone" re: 'S.TimeZoneSeries'
 
-use of 'TimeZoneSeries' is preferred when converting from 'UTCTime' to 'DatePart' -}
+use of 'S.TimeZoneSeries' is preferred when converting from 'C.UTCTime' to 'DatePart' -}
 
 
 
diff --git a/src/Data/Time/Hora/Zone.hs b/src/Data/Time/Hora/Zone.hs
--- a/src/Data/Time/Hora/Zone.hs
+++ b/src/Data/Time/Hora/Zone.hs
@@ -11,7 +11,7 @@
 
 -- see man tzfile for common olson file locations
 getTimeZoneSeriesFromOlsonFile "\/usr\/share\/zoneinfo\/Chile\/Continental" >>=
-    \\(chile1::TimeZoneSeries) -> ...            
+    \\(chile1 :: TimeZoneSeries) -> ...
 @       -}
 module Data.Time.Hora.Zone where
 
@@ -19,12 +19,11 @@
 import Data.Time.Hora.Type
 
 
--- ^ convert 'DatePart' from one 'TimeZone' to another        
+-- ^ convert 'DatePart' from one 'Data.Time.LocalTime.TimeZone' to another
 toTimeZone::(TwoInt a b, Tz' tz) => 
     tz -- ^ target timezone
     -> (Tz (DatePart a)) -- ^ local (to source timezone) date & time 
         -> (Maybe (Tz (DatePart b))) {- ^ local (to target timezone) date & time
             
                         'Nothing' if source date is invalid-} 
-toTimeZone series0 dp0 = toUtc dp0 >>= Just . (fromUtc' series0)
-                
+toTimeZone series0 dp0 = fromUtc' series0 <$> toUtc dp0
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -1,28 +1,30 @@
 module Main where
 
+import Test.Hspec
+import qualified Test.TestAncientDate as A
+import qualified Test.TestCheckOverflow as Of
 import qualified Test.TestConvert as Conv
+import qualified Test.TestDatePart as Dp
+import qualified Test.TestDatePartSmall as Sm
+import qualified Test.TestDatePartSmallConvert as Smc
+import qualified Test.TestDatePartSmallDoc as Smd
 import qualified Test.TestDiffTime as T
 import qualified Test.TestDmyHm as D
-import qualified Test.TestDatePart as Dp
-import qualified Test.TestUtc as U
+import qualified Test.TestFormat as Tf
 import qualified Test.TestFuture as Fut
 import qualified Test.TestPico as P
 import qualified Test.TestPico2 as P2
+import qualified Test.TestRoundtripPicoMilli as Pm
 import qualified Test.TestSome as Tcom
-import qualified Test.TestFormat as Tf
+import qualified Test.TestStamp as Stamp
+import qualified Test.TestStorageSize as Sto
 import qualified Test.TestTime as Tt
 import qualified Test.TestUTCTimeBin as Bin
+import qualified Test.TestUtc as U
 import qualified Test.TestZone as Z
-import qualified Test.TestAncientDate as A
-import qualified Test.TestDatePartSmall as Sm
-import qualified Test.TestStorageSize as Sto
-import qualified Test.TestDatePartSmallConvert as Smc
-import qualified Test.TestRoundtripPicoMilli as Pm
-import qualified Test.TestDatePartSmallDoc as Smd
-import qualified Test.TestCheckOverflow as Of
 
 main::IO()
-main = do
+main = hspec $ do
         Of.main
         T.main
         Conv.main
@@ -43,3 +45,4 @@
         Smc.main
         Pm.main
         Smd.main
+        Stamp.main
diff --git a/test/Test/TestAncientDate.hs b/test/Test/TestAncientDate.hs
--- a/test/Test/TestAncientDate.hs
+++ b/test/Test/TestAncientDate.hs
@@ -6,9 +6,8 @@
 import Debug.Trace
 import Test.Hspec
 
-main::IO()
-main = hspec $ do
-   describe "day way in the past" $ do
+main :: SpecWith ()
+main = describe "day way in the past" $ do
       it "year 1" $ do
          traceIO $ "year 1: " <> (show utc1)
          traceIO $ "year 1: " <> (show utcbin1)
diff --git a/test/Test/TestCheckOverflow.hs b/test/Test/TestCheckOverflow.hs
--- a/test/Test/TestCheckOverflow.hs
+++ b/test/Test/TestCheckOverflow.hs
@@ -5,9 +5,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-   describe "TestCheckOverflow" $ do
+main :: SpecWith()
+main = describe "TestCheckOverflow" $ do
       it "addition succeeds" $ do
          let result1 = checkOverflow Min' 3 (+) 10
          result1 `shouldBe` (Min' 13)
diff --git a/test/Test/TestConvert.hs b/test/Test/TestConvert.hs
--- a/test/Test/TestConvert.hs
+++ b/test/Test/TestConvert.hs
@@ -6,15 +6,15 @@
 import Test.Hspec
 
 
-main::IO()
+main:: SpecWith ()
 main = do 
     test
     doc
 
 
 
-test::IO()
-test = hspec $ do
+test:: SpecWith ()
+test = do
        describe "Case.Convert" $ do
           it "pico 1" $ do
               toPico (Sec $ i 12) `shouldBe` (toPico $ Milli $ toMilli $ Sec $ i 12)
@@ -38,9 +38,8 @@
               s1 = toSec (Milli m1)::Int
               i3 = 3::Int
 
-doc::IO()
-doc = hspec $ do
-    describe "doc Convert" $ do
+doc:: SpecWith ()
+doc = describe "doc Convert" $ do
         it "toPicos milli" $ toPico (Milli 1) `shouldBe` 1000000000
         it "toPicos sec" $  toPico (Sec 1) `shouldBe` 1000000000000
         it "toMillis sec" $  toMilli (Sec 1) `shouldBe` 1000
diff --git a/test/Test/TestDatePart.hs b/test/Test/TestDatePart.hs
--- a/test/Test/TestDatePart.hs
+++ b/test/Test/TestDatePart.hs
@@ -7,9 +7,8 @@
 default (Int)
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestDatePart" $ do
+main:: SpecWith ()
+main = describe "Test.TestDatePart" $ do
           it "Ord" $ do
             (dp 1 1 1 1 1 1 1)  `shouldSatisfy` (== (dp 1 1 1 1 1 1 1))
             (dp 1 1 1 1 1 1 1)  `shouldSatisfy` (<= (dp 1 1 1 1 1 1 1))
diff --git a/test/Test/TestDatePartSmall.hs b/test/Test/TestDatePartSmall.hs
--- a/test/Test/TestDatePartSmall.hs
+++ b/test/Test/TestDatePartSmall.hs
@@ -6,8 +6,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
+main:: SpecWith ()
+main = do
    describe "TestDatePartSmall merge" $ do
       it "1 Day <> Time" $ do
            Day 2 <> Time 3 5 `shouldBe` DatePartSmall 2 3 5
diff --git a/test/Test/TestDatePartSmallConvert.hs b/test/Test/TestDatePartSmallConvert.hs
--- a/test/Test/TestDatePartSmallConvert.hs
+++ b/test/Test/TestDatePartSmallConvert.hs
@@ -12,9 +12,8 @@
 import Prelude as P
 import Test.Hspec
 
-main::IO()
-main = hspec $ do
-   describe "TestDatePartSmallConvert" $ do
+main:: SpecWith ()
+main = describe "TestDatePartSmallConvert" $ do
       it "now <-> DatePartSmall" $ do
          now1 <- now::IO UTCTime
          let small1 = fromUtc now1::DatePartSmall
@@ -36,5 +35,6 @@
              dp2 = fromUtc utcNow2::DatePart Int
              dp3 = fromUtc utcIncr3::DatePart Int
          traceIO $ "increment DatePartSmall by 1 day in minutes dp2: " <> show dp2
-         traceIO $ "increment DatePartSmall by 1 day in minutes dp3: " <>show dp3
-         day dp3 P.- day dp2 `shouldBe` 1
+         traceIO $ "increment DatePartSmall by 1 day in minutes dp3: " <> show dp3
+         if month dp3 /= month dp2 then day dp3 `shouldBe` 1
+         else day dp3 P.- day dp2 `shouldBe` 1
diff --git a/test/Test/TestDatePartSmallDoc.hs b/test/Test/TestDatePartSmallDoc.hs
--- a/test/Test/TestDatePartSmallDoc.hs
+++ b/test/Test/TestDatePartSmallDoc.hs
@@ -12,8 +12,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
+main:: SpecWith ()
+main = do
    describe "TestDatePartSmall" $ do
       it "day 1" $ do
            mkDay 1 1 1 `shouldBe` (Day 1)
diff --git a/test/Test/TestDiffTime.hs b/test/Test/TestDiffTime.hs
--- a/test/Test/TestDiffTime.hs
+++ b/test/Test/TestDiffTime.hs
@@ -9,10 +9,8 @@
 import Test.Hspec
 
 
-
-main::IO()
-main = hspec $ do
-       describe "TestDiffTime" $ do
+main :: SpecWith ()
+main = describe "TestDiffTime" $ do
           it "diff time" $ do
             t1 <- getCurrentTime
             threadDelay 7000
diff --git a/test/Test/TestDmyHm.hs b/test/Test/TestDmyHm.hs
--- a/test/Test/TestDmyHm.hs
+++ b/test/Test/TestDmyHm.hs
@@ -4,9 +4,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestDmyHm" $ do
+main :: SpecWith ()
+main = describe "Test.TestDmyHm" $ do
           it "case 1" $ do
             a1 `shouldSatisfy` (< b1)
         where a1 = DatePart {
diff --git a/test/Test/TestFormat.hs b/test/Test/TestFormat.hs
--- a/test/Test/TestFormat.hs
+++ b/test/Test/TestFormat.hs
@@ -8,8 +8,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
+main::SpecWith ()
+main = do
        describe "Test.TestFormat" $ do
           it "prefix tab \n Offset" $ do
             ts ["prefix", Tab, "postfix", Crlf, Offset] >>= utc
diff --git a/test/Test/TestFuture.hs b/test/Test/TestFuture.hs
--- a/test/Test/TestFuture.hs
+++ b/test/Test/TestFuture.hs
@@ -7,9 +7,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Case.TestFuture" $ do
+main:: SpecWith ()
+main = describe "Case.TestFuture" $ do
           it "3 second from now" $ do
             t1 <- getCurrentTime
             traceIO $ show t1
diff --git a/test/Test/TestPico.hs b/test/Test/TestPico.hs
--- a/test/Test/TestPico.hs
+++ b/test/Test/TestPico.hs
@@ -11,9 +11,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestPico" $ do
+main:: SpecWith ()
+main = describe "Test.TestPico" $ do
           it "now" $ do
             (now::IO (DatePart Int)) >>= traceIO . show
             1 `shouldBe` 1
diff --git a/test/Test/TestPico2.hs b/test/Test/TestPico2.hs
--- a/test/Test/TestPico2.hs
+++ b/test/Test/TestPico2.hs
@@ -5,9 +5,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestPico2" $ do
+main:: SpecWith ()
+main = describe "Test.TestPico2" $ do
           it "case 1" $ do
             traceIO $ show p1
             let MkFixed p2 = p1
diff --git a/test/Test/TestRoundtripPicoMilli.hs b/test/Test/TestRoundtripPicoMilli.hs
--- a/test/Test/TestRoundtripPicoMilli.hs
+++ b/test/Test/TestRoundtripPicoMilli.hs
@@ -10,9 +10,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-   describe "TestRoundtripPicoMilli" $ do
+main:: SpecWith ()
+main = describe "TestRoundtripPicoMilli" $ do
       it "round trip pico" $ do
          now1 <- now::IO UTCTime
          let dp1 = fromUtc now1::DatePart Int
diff --git a/test/Test/TestSome.hs b/test/Test/TestSome.hs
--- a/test/Test/TestSome.hs
+++ b/test/Test/TestSome.hs
@@ -7,9 +7,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestCommon" $ do
+main:: SpecWith ()
+main = describe "Test.TestCommon" $ do
           it "iso" $ do
             ts iso >>= utc 
             1 `shouldBe` 1
diff --git a/test/Test/TestStamp.hs b/test/Test/TestStamp.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/TestStamp.hs
@@ -0,0 +1,31 @@
+module Test.TestStamp where
+
+import Debug.Trace
+import Test.Hspec
+import Data.Time.Clock
+import Data.Time.Hora.Part
+import Data.Time.Hora.Stamp
+import Data.Time.Hora.Type
+
+
+main:: SpecWith ()
+main = describe "Test.TestStamp" $ do
+      it "now : UTC Time" $ do
+         result1 :: UTCTime <- now
+         traceIO $ show ("UTCTime",result1)
+      it "now : DatePart Int" $ do
+         result1 :: DatePart Int <- now
+         traceIO $ show ("DatePart",result1)
+      it "now : Tz (DatePart Int)" $ do
+         result1 :: Tz (DatePart Int) <- now
+         traceIO $ show ("Tz DatePart",result1)
+      it "now : DatePartSmall" $ do
+         result1 :: DatePartSmall <- now
+         traceIO $ show ("DatePartSmall",result1)
+         let utc2 = toUtc result1
+         traceIO $ show ("DatePartSmall -> UTCTime",utc2)
+      it "now : Tz DatePartSmall" $ do
+         result1 :: Tz DatePartSmall <- now
+         let utc2 = toUtc <$> result1
+         traceIO $ show ("Tz DatePartSmall -> Tz UTCTime", utc2)
+
diff --git a/test/Test/TestStorageSize.hs b/test/Test/TestStorageSize.hs
--- a/test/Test/TestStorageSize.hs
+++ b/test/Test/TestStorageSize.hs
@@ -13,9 +13,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-   describe "compare binary size" $ do
+main:: SpecWith ()
+main = describe "compare binary size" $ do
       it "Min 10" $ do
          let result1 = Min 10
              bin2 = encode result1
diff --git a/test/Test/TestTime.hs b/test/Test/TestTime.hs
--- a/test/Test/TestTime.hs
+++ b/test/Test/TestTime.hs
@@ -7,9 +7,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestTime" $ do
+main:: SpecWith ()
+main = describe "Test.TestTime" $ do
           it "timestamp" $ do
             ts t >>= traceIO
             1 `shouldBe` 1
diff --git a/test/Test/TestUTCTimeBin.hs b/test/Test/TestUTCTimeBin.hs
--- a/test/Test/TestUTCTimeBin.hs
+++ b/test/Test/TestUTCTimeBin.hs
@@ -11,9 +11,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-   describe "round trip convert & serialize UTCTime via UTCTimeBin" $ do
+main:: SpecWith ()
+main = describe "round trip convert & serialize UTCTime via UTCTimeBin" $ do
       it "round trip convert" $ do
          utc1 <- now::IO UTCTime
          let utcbin2 = fromUtc utc1::UTCTimeBin
diff --git a/test/Test/TestUtc.hs b/test/Test/TestUtc.hs
--- a/test/Test/TestUtc.hs
+++ b/test/Test/TestUtc.hs
@@ -8,9 +8,8 @@
 import Debug.Trace
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestUtc" $ do
+main:: SpecWith ()
+main = describe "Test.TestUtc" $ do
           it "invalid date" $ do
             toUtc (DatePart {year = 2010, month = 20, day = 1, hour = 0, minute = 1 ,second = 1, pico = 0})
                 `shouldBe` Nothing
diff --git a/test/Test/TestZone.hs b/test/Test/TestZone.hs
--- a/test/Test/TestZone.hs
+++ b/test/Test/TestZone.hs
@@ -11,9 +11,8 @@
 import Test.Hspec
 
 
-main::IO()
-main = hspec $ do
-       describe "Test.TestZone" $ do
+main:: SpecWith ()
+main = describe "Test.TestZone" $ do
           it "UTC to Chile" $ do
             chile1 <- getTimeZoneSeriesFromOlsonFile "./test/TimeSeriesData/ChileContinental"
             china1 <- getTimeZoneSeriesFromOlsonFile "./test/TimeSeriesData/ROC"