diff --git a/purescript-iso.cabal b/purescript-iso.cabal
--- a/purescript-iso.cabal
+++ b/purescript-iso.cabal
@@ -2,10 +2,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: c6397c41d058e0b7c2155fd2e147eb98d3f4dd5c7b0782c38520d8c5f2ac8f78
+-- hash: 3027dbec58707b55ea24b591ca5fb8d9bad467ac4211f9a7777444dbded91d3a
 
 name:           purescript-iso
-version:        0.0.1.1
+version:        0.0.1.2
 synopsis:       Isomorphic trivial data type definitions over JSON
 description:    Please see the README on GitHub at <https://github.com/githubuser/purescript-iso#readme>
 category:       Web
@@ -27,6 +27,7 @@
 
 library
   exposed-modules:
+      Data.Aeson.JSONDateTime
       Data.Aeson.JSONEither
       Data.Aeson.JSONTuple
       Data.Aeson.JSONUnit
@@ -50,6 +51,7 @@
     , stm
     , strict
     , text
+    , time
     , utf8-string
     , uuid
     , zeromq4-haskell
diff --git a/src/Data/Aeson/JSONDateTime.hs b/src/Data/Aeson/JSONDateTime.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Aeson/JSONDateTime.hs
@@ -0,0 +1,38 @@
+{-# LANGUAGE
+    GeneralizedNewtypeDeriving
+  , DeriveGeneric
+  #-}
+
+module Data.Aeson.JSONDateTime where
+
+import Data.Time
+  ( UTCTime, formatTime, iso8601DateFormat, defaultTimeLocale
+  , getCurrentTime, parseTimeOrError)
+import Data.Aeson (ToJSON, FromJSON, decode)
+import qualified Data.ByteString.Lazy.UTF8 as LBS8
+import Test.QuickCheck (Arbitrary (..))
+import GHC.Generics (Generic)
+import System.IO.Unsafe (unsafePerformIO)
+
+
+newtype JSONDateTime = JSONDateTime
+  { getJSONDateTime :: UTCTime
+  } deriving (Eq, Ord, Show, Generic, ToJSON, FromJSON)
+
+
+jsonDateTime :: UTCTime -> JSONDateTime
+jsonDateTime now =
+  let p = take 3 (formatTime defaultTimeLocale "%q" now)
+      s = formatTime defaultTimeLocale (iso8601DateFormat $ Just "%H:%M:%S") now
+      s' = s ++ "." ++ p ++ "Z"
+  in  case decode $ LBS8.fromString $ show s' of
+        Just x -> JSONDateTime x
+        Nothing -> error s'
+
+
+instance Arbitrary JSONDateTime where
+  arbitrary =
+    let go = unsafePerformIO $ do
+          now <- getCurrentTime
+          pure (jsonDateTime now)
+    in  go `seq` pure go
diff --git a/src/Data/Aeson/JSONEither.hs b/src/Data/Aeson/JSONEither.hs
--- a/src/Data/Aeson/JSONEither.hs
+++ b/src/Data/Aeson/JSONEither.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE
     OverloadedStrings
+  , DeriveGeneric
   #-}
 
 module Data.Aeson.JSONEither where
@@ -9,12 +10,13 @@
 import Control.Applicative ((<|>))
 import Test.QuickCheck (Arbitrary (..))
 import Test.QuickCheck.Gen (oneof)
+import GHC.Generics (Generic)
 
 
 data JSONEither a b
   = JSONLeft a
   | JSONRight b
-  deriving (Eq, Show)
+  deriving (Eq, Ord, Show, Generic)
 
 instance (ToJSON a, ToJSON b) => ToJSON (JSONEither a b) where
   toJSON x = case x of
diff --git a/src/Data/Aeson/JSONTuple.hs b/src/Data/Aeson/JSONTuple.hs
--- a/src/Data/Aeson/JSONTuple.hs
+++ b/src/Data/Aeson/JSONTuple.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE
     OverloadedStrings
+  , DeriveGeneric
   #-}
 
 module Data.Aeson.JSONTuple where
@@ -7,10 +8,11 @@
 import Data.Aeson (ToJSON (..), FromJSON (..), Value (Object), object, (.=), (.:))
 import Data.Aeson.Types (typeMismatch)
 import Test.QuickCheck (Arbitrary (..))
+import GHC.Generics (Generic)
 
 
 data JSONTuple a b = JSONTuple a b
-  deriving (Eq, Show)
+  deriving (Eq, Ord, Show, Generic)
 
 instance (ToJSON a, ToJSON b) => ToJSON (JSONTuple a b) where
   toJSON (JSONTuple a b) = object ["l" .= a, "r" .= b]
diff --git a/src/Data/Aeson/JSONUnit.hs b/src/Data/Aeson/JSONUnit.hs
--- a/src/Data/Aeson/JSONUnit.hs
+++ b/src/Data/Aeson/JSONUnit.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE
     OverloadedStrings
+  , DeriveGeneric
   #-}
 
 module Data.Aeson.JSONUnit where
@@ -7,10 +8,11 @@
 import Data.Aeson (ToJSON (..), FromJSON (..), Value (String))
 import Data.Aeson.Types (typeMismatch)
 import Test.QuickCheck (Arbitrary (..))
+import GHC.Generics (Generic)
 
 
 data JSONUnit = JSONUnit
-  deriving (Eq, Show)
+  deriving (Eq, Ord, Show, Generic)
 
 instance Arbitrary JSONUnit where
   arbitrary = pure JSONUnit
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -5,6 +5,7 @@
 import Data.Aeson.JSONUnit (JSONUnit)
 import Data.Aeson.JSONEither (JSONEither)
 import Data.Aeson.JSONTuple (JSONTuple)
+import Data.Aeson.JSONDateTime (JSONDateTime)
 import Data.Time (UTCTime)
 import Data.Time.Calendar (Day)
 
@@ -49,7 +50,7 @@
   registerTopic "JSONEither" (Proxy :: Proxy (JSONEither JSONUnit JSONUnit))
   registerTopic "JSONTuple" (Proxy :: Proxy (JSONTuple JSONUnit JSONUnit))
   registerTopic "JSONDate" (Proxy :: Proxy Day)
-  -- registerTopic "JSONDateTime" (Proxy :: Proxy UTCTime)
+  registerTopic "JSONDateTime" (Proxy :: Proxy JSONDateTime)
 
 
 jsonIso :: ToJSON a => FromJSON a => Eq a => a -> Result