diff --git a/Makefile b/Makefile
index 571d69a1514b147feb68a107392a1ed8f4301c71..46d68a21a08d64cf0076965bbc38c2a8f7bdb050 100644
--- a/Makefile
+++ b/Makefile
@@ -19,6 +19,6 @@ doc: sources
 	haddock -h -o haddock `cat sources`
 
 clean:
-	rm -f sources
+	rm -f sources haddock
 	cd time && make clean
 	cd fixed && make clean
diff --git a/README b/README
new file mode 100644
index 0000000000000000000000000000000000000000..76616547033634e932358a13c82717e2878bafde
--- /dev/null
+++ b/README
@@ -0,0 +1,24 @@
+This contains two packages, "fixed" and "time". They can each be built with Cabal. "time" depends on "fixed".
+
+  cd fixed
+  runghc Setup.hs configure
+  runghc Setup.hs build
+  sudo runghc Setup.hs install
+  cd ..
+
+  cd time
+  runghc Setup.hs configure
+  runghc Setup.hs build
+  sudo runghc Setup.hs install
+  cd ..
+
+You can use it with ghci:
+
+  $ ghci
+  Prelude> :m +Data.Time
+  Prelude Data.Time> t <- getCurrentTime
+  Prelude Data.Time> t
+  2006-02-06 06:31:43.859082 UTC
+  Prelude Data.Time> zt <- getZonedTime
+  Prelude Data.Time> zt
+  2006-02-05 22:32:32.948607 PST
diff --git a/time/Data/Time/Clock/UTCDiff.hs b/time/Data/Time/Clock/UTCDiff.hs
new file mode 100644
index 0000000000000000000000000000000000000000..66a2a4833a2366012bab3aafe5beda7e07629cf4
--- /dev/null
+++ b/time/Data/Time/Clock/UTCDiff.hs
@@ -0,0 +1,15 @@
+{-# OPTIONS -Wall -Werror #-}
+
+-- #hide
+module Data.Time.Clock.UTCDiff where
+
+import Data.Time.Clock.POSIX
+import Data.Time.Clock.UTC
+
+-- | addUTCTime a b = a + b
+addUTCTime :: NominalDiffTime -> UTCTime -> UTCTime
+addUTCTime x t = posixSecondsToUTCTime (x + (utcTimeToPOSIXSeconds t))
+
+-- | diffUTCTime a b = a - b
+diffUTCTime :: UTCTime -> UTCTime -> NominalDiffTime
+diffUTCTime a b = (utcTimeToPOSIXSeconds a) - (utcTimeToPOSIXSeconds b)