diff --git a/backends/GenerateC.hs b/backends/GenerateC.hs
index e6f6570..2406b73 100644
--- a/backends/GenerateC.hs
+++ b/backends/GenerateC.hs
@@ -324,7 +324,7 @@ cgetScalarType A.Int32 = Just "int32_t"
 cgetScalarType A.Int64 = Just "int64_t"
 cgetScalarType A.Real32 = Just "float"
 cgetScalarType A.Real64 = Just "double"
-cgetScalarType A.Timer = Just "Time"
+cgetScalarType (A.Timer A.OccamTimer) = Just "Time"
 cgetScalarType A.Time = Just "Time"
 cgetScalarType _ = Nothing
 
diff --git a/backends/GenerateCPPCSP.hs b/backends/GenerateCPPCSP.hs
index 867b4ec..80957c6 100644
--- a/backends/GenerateCPPCSP.hs
+++ b/backends/GenerateCPPCSP.hs
@@ -642,7 +642,7 @@ cppgetScalarType A.Int32 = Just "int32_t"
 cppgetScalarType A.Int64 = Just "int64_t"
 cppgetScalarType A.Real32 = Just "float"
 cppgetScalarType A.Real64 = Just "double"
-cppgetScalarType A.Timer = Just "csp::Time"
+cppgetScalarType (A.Timer A.OccamTimer) = Just "csp::Time"
 cppgetScalarType A.Time = Just "csp::Time"
 cppgetScalarType _ = Nothing
 
diff --git a/backends/GenerateCTest.hs b/backends/GenerateCTest.hs
index f973c47..a25edaa 100644
--- a/backends/GenerateCTest.hs
+++ b/backends/GenerateCTest.hs
@@ -230,7 +230,7 @@ testGenType = TestList
   ,testBothSame "GenType 102" "int*" (tcall genType $ A.Array [dimension 5, A.UnknownDimension] A.Int) 
   ,testBothSame "GenType 103" "foo" (tcall genType $ A.Record (simpleName "foo")) 
   ,testBoth "GenType 200" "Time" "csp::Time" (tcall genType A.Time) 
-  ,testBoth "GenType 201" "Time" "csp::Time" (tcall genType A.Timer) 
+  ,testBoth "GenType 201" "Time" "csp::Time" (tcall genType $ A.Timer A.OccamTimer) 
   
   ,testBothSame "GenType 250" "int*" (tcall genType $ A.Mobile $ A.Array [dimension 5, dimension 2, dimension 9] A.Int) 
   ,testBothSame "GenType 251" "int*" (tcall genType $ A.Mobile $ A.Array [dimension 5, A.UnknownDimension] A.Int) 
@@ -486,9 +486,9 @@ testDeclaration = TestList
 
   --Timers:
   ,testBoth "genDeclaration 500" "Time foo;" "csp::Time foo;"
-   (tcall3 genDeclaration A.Timer foo False)
+   (tcall3 genDeclaration (A.Timer A.OccamTimer) foo False)
   ,testBoth "genDeclaration 501" "Time foo[20];" "csp::Time foo[20];"
-   (tcall3 genDeclaration (A.Array [dimension 20] A.Timer) foo False)
+   (tcall3 genDeclaration (A.Array [dimension 20] (A.Timer A.OccamTimer)) foo False)
  ]
  where
    stateR t = defRecord "REC" "bar" t
diff --git a/common/ShowCode.hs b/common/ShowCode.hs
index 8d47a94..9265d34 100644
--- a/common/ShowCode.hs
+++ b/common/ShowCode.hs
@@ -223,7 +223,7 @@ instance ShowOccam A.Type where
   showOccamM A.Real32 = tell ["REAL32"]
   showOccamM A.Real64 = tell ["REAL64"]
   showOccamM A.Any = tell ["ANY"]
-  showOccamM A.Timer = tell ["TIMER"]
+  showOccamM (A.Timer _) = tell ["TIMER"]
   showOccamM A.Time = tell ["TIME"]
 
   showOccamM (A.Mobile t) = tell ["MOBILE "] >> showOccamM t
diff --git a/data/AST.hs b/data/AST.hs
index ff1e767..b7217fc 100644
--- a/data/AST.hs
+++ b/data/AST.hs
@@ -98,6 +98,13 @@ data ChanAttributes = ChanAttributes {
   }
   deriving (Show, Eq, Typeable, Data)
 
+-- | In future we will probably add more timers to this list, especially for
+-- occam.  But for now we just differentiate between an occam timer (which
+-- reads into something of type Int), and a Rain timer (which reads into something
+-- of type Time).
+data TimerType = OccamTimer | RainTimer
+  deriving (Eq, Show, Ord, Typeable, Data)
+
 -- | A data or protocol type.
 -- The two concepts aren't unified in occam, but they are here, because it
 -- makes sense to be able to ask what type a particular name is defined to
@@ -132,7 +139,7 @@ data Type =
   -- | A counted input or output.
   | Counted Type Type
   | Any
-  | Timer
+  | Timer TimerType
   | Time
   | Port Type
   | Mobile Type
diff --git a/frontends/ParseOccam.hs b/frontends/ParseOccam.hs
index 6e1d574..3300e98 100644
--- a/frontends/ParseOccam.hs
+++ b/frontends/ParseOccam.hs
@@ -628,7 +628,7 @@ channelType
 
 timerType :: OccParser A.Type
 timerType
-    =   do { sTIMER; return $ A.Timer }
+    =   do { sTIMER; return $ A.Timer A.OccamTimer }
     <|> arrayType timerType
     <?> "timer type"
 
@@ -1969,7 +1969,7 @@ actual (A.Formal am t n)
             _ ->
               case stripArrayType t of
                 A.Chan {} -> var (channelOfType t)
-                A.Timer -> var timer
+                A.Timer {} -> var timer
                 A.Port _ -> var (portOfType t)
                 _ -> var (variableOfType t)
     <?> "actual of type " ++ showOccam t ++ " for " ++ show n
diff --git a/frontends/RainPasses.hs b/frontends/RainPasses.hs
index b6219d7..5c70f6d 100644
--- a/frontends/RainPasses.hs
+++ b/frontends/RainPasses.hs
@@ -298,7 +298,7 @@ excludeNonRainFeatures = excludeConstr
   [ con0 A.Real32
    ,con0 A.Real64
    ,con2 A.Counted
-   ,con0 A.Timer
+   ,con1 A.Timer
    ,con1 A.Port
    ,con2 A.BytesInExpr
    ,con2 A.BytesInType