diff --git a/Annex/VectorClock.hs b/Annex/VectorClock.hs
index 24a6bd1fd4..c7f6d6336d 100644
--- a/Annex/VectorClock.hs
+++ b/Annex/VectorClock.hs
@@ -21,7 +21,7 @@ import Utility.QuickCheck
 -- | Some very old logs did not have any time stamp at all;
 -- Unknown is used for those.
 data VectorClock = Unknown | VectorClock POSIXTime
-	deriving (Eq, Ord, Show)
+	deriving (Eq, Ord)
 
 -- Unknown is oldest.
 prop_VectorClock_sane :: Bool
@@ -37,3 +37,10 @@ currentVectorClock = go =<< getEnv "GIT_ANNEX_VECTOR_CLOCK"
 	go (Just s) = case parsePOSIXTime s of
 		Just t -> return (VectorClock t)
 		Nothing -> VectorClock <$> getPOSIXTime
+
+formatVectorClock :: VectorClock -> String
+formatVectorClock  Unknown = "0"
+formatVectorClock (VectorClock t) = show t
+
+parseVectorClock :: String -> Maybe VectorClock
+parseVectorClock t = VectorClock <$> parsePOSIXTime t
diff --git a/Logs/MapLog.hs b/Logs/MapLog.hs
index 7fe9e5782a..a881eae341 100644
--- a/Logs/MapLog.hs
+++ b/Logs/MapLog.hs
@@ -19,7 +19,6 @@ module Logs.MapLog (
 
 import Common
 import Annex.VectorClock
-import Logs.TimeStamp
 import Logs.Line
 
 import qualified Data.Map as M
@@ -27,7 +26,7 @@ import qualified Data.Map as M
 data LogEntry v = LogEntry
 	{ changed :: VectorClock
 	, value :: v
-	} deriving (Eq, Show)
+	} deriving (Eq)
 
 type MapLog f v = M.Map f (LogEntry v)
 
@@ -43,9 +42,9 @@ parseMapLog :: Ord f => (String -> Maybe f) -> (String -> Maybe v) -> String ->
 parseMapLog fieldparser valueparser = M.fromListWith best . mapMaybe parse . splitLines
   where
 	parse line = do
-		let (ts, rest) = splitword line
+		let (sc, rest) = splitword line
 		    (sf, sv) = splitword rest
-		c <- VectorClock <$> parsePOSIXTime ts
+		c <- parseVectorClock sc
 		f <- fieldparser sf
 		v <- valueparser sv
 		Just (f, LogEntry c v)
diff --git a/Logs/Presence/Pure.hs b/Logs/Presence/Pure.hs
index 03cbdcdc1a..8fc1541776 100644
--- a/Logs/Presence/Pure.hs
+++ b/Logs/Presence/Pure.hs
@@ -9,7 +9,6 @@ module Logs.Presence.Pure where
 
 import Annex.Common
 import Annex.VectorClock
-import Logs.TimeStamp
 import Logs.Line
 import Utility.QuickCheck
 
@@ -19,7 +18,10 @@ data LogLine = LogLine
 	{ date :: VectorClock
 	, status :: LogStatus
 	, info :: String
-	} deriving (Eq, Show)
+	} deriving (Eq)
+
+instance Show LogLine where
+	show l = "LogLine " ++ formatVectorClock (date l) ++ show (status l) ++ " " ++ show (info l)
 
 data LogStatus = InfoPresent | InfoMissing | InfoDead
 	deriving (Eq, Show, Bounded, Enum)
@@ -29,12 +31,12 @@ parseLog :: String -> [LogLine]
 parseLog = mapMaybe parseline . splitLines
   where
 	parseline l = LogLine
-		<$> (VectorClock <$> parsePOSIXTime d)
+		<$> parseVectorClock c
 		<*> parseStatus s
 		<*> pure rest
 	  where
-		(d, pastd) = separate (== ' ') l
-		(s, rest) = separate (== ' ') pastd
+		(c, pastc) = separate (== ' ') l
+		(s, rest) = separate (== ' ') pastc
 
 parseStatus :: String -> Maybe LogStatus
 parseStatus "1" = Just InfoPresent
@@ -46,7 +48,7 @@ parseStatus _ = Nothing
 showLog :: [LogLine] -> String
 showLog = unlines . map genline
   where
-	genline (LogLine d s i) = unwords [show d, genstatus s, i]
+	genline (LogLine c s i) = unwords [formatVectorClock c, genstatus s, i]
 	genstatus InfoPresent = "1"
 	genstatus InfoMissing = "0"
 	genstatus InfoDead = "X"
diff --git a/Logs/SingleValue.hs b/Logs/SingleValue.hs
index 24242c83ff..1a6181f56a 100644
--- a/Logs/SingleValue.hs
+++ b/Logs/SingleValue.hs
@@ -15,7 +15,6 @@ module Logs.SingleValue where
 
 import Annex.Common
 import qualified Annex.Branch
-import Logs.TimeStamp
 import Logs.Line
 import Annex.VectorClock
 
@@ -28,21 +27,21 @@ class SingleValueSerializable v where
 data LogEntry v = LogEntry
 	{ changed :: VectorClock
 	, value :: v
-	} deriving (Eq, Show, Ord)
+	} deriving (Eq, Ord)
 
 type Log v = S.Set (LogEntry v)
 
 showLog :: (SingleValueSerializable v) => Log v -> String
 showLog = unlines . map showline . S.toList
   where
-	showline (LogEntry t v) = unwords [show t, serialize v]
+	showline (LogEntry c v) = unwords [formatVectorClock c, serialize v]
 
 parseLog :: (Ord v, SingleValueSerializable v) => String -> Log v
 parseLog = S.fromList . mapMaybe parse . splitLines
   where
 	parse line = do
-		let (ts, s) = splitword line
-		c <- VectorClock <$> parsePOSIXTime ts
+		let (sc, s) = splitword line
+		c <- parseVectorClock sc
 		v <- deserialize s
 		Just (LogEntry c v)
 	splitword = separate (== ' ')
diff --git a/Logs/Transitions.hs b/Logs/Transitions.hs
index 79acb87dd9..0a90f118fc 100644
--- a/Logs/Transitions.hs
+++ b/Logs/Transitions.hs
@@ -16,7 +16,6 @@ module Logs.Transitions where
 
 import Annex.Common
 import Annex.VectorClock
-import Logs.TimeStamp
 import Logs.Line
 
 import qualified Data.Set as S
@@ -32,7 +31,7 @@ data Transition
 data TransitionLine = TransitionLine
 	{ transitionStarted :: VectorClock
 	, transition :: Transition
-	} deriving (Show, Ord, Eq)
+	} deriving (Ord, Eq)
 
 type Transitions = S.Set TransitionLine
 
@@ -63,16 +62,16 @@ parseTransitionsStrictly source = fromMaybe badsource . parseTransitions
 	badsource = giveup $ "unknown transitions listed in " ++ source ++ "; upgrade git-annex!"
 
 showTransitionLine :: TransitionLine -> String
-showTransitionLine (TransitionLine ts t) = unwords [show t, show ts]
+showTransitionLine (TransitionLine c t) = unwords [show t, formatVectorClock c]
 
 parseTransitionLine :: String -> Maybe TransitionLine
 parseTransitionLine s = TransitionLine
-	<$> (VectorClock <$> parsePOSIXTime ds)
+	<$> parseVectorClock cs
 	<*> readish ts
   where
 	ws = words s
 	ts = Prelude.head ws
-	ds = unwords $ Prelude.tail ws
+	cs = unwords $ Prelude.tail ws
 
 combineTransitions :: [Transitions] -> Transitions
 combineTransitions = S.unions
diff --git a/Logs/UUIDBased.hs b/Logs/UUIDBased.hs
index fd1cd7c2d5..4f32c19c7c 100644
--- a/Logs/UUIDBased.hs
+++ b/Logs/UUIDBased.hs
@@ -35,7 +35,6 @@ import Common
 import Types.UUID
 import Annex.VectorClock
 import Logs.MapLog
-import Logs.TimeStamp
 import Logs.Line
 
 type Log v = MapLog UUID v
@@ -68,15 +67,12 @@ parseLogWithUUID parser = M.fromListWith best . mapMaybe parse . splitLines
 		u = toUUID $ Prelude.head ws
 		t = Prelude.last ws
 		ts
-			| tskey `isPrefixOf` t =
-				pdate $ drop 1 $ dropWhile (/= '=') t
+			| tskey `isPrefixOf` t = fromMaybe Unknown $
+				parseVectorClock $ drop 1 $ dropWhile (/= '=') t
 			| otherwise = Unknown
 		info
 			| ts == Unknown = drop 1 ws
 			| otherwise = drop 1 $ beginning ws
-		pdate s = case parsePOSIXTime s of
-			Nothing -> Unknown
-			Just d -> VectorClock d
 
 showLogNew :: (v -> String) -> Log v -> String
 showLogNew = showMapLog fromUUID