diff --git a/src/Hash2Pub/PostService.hs b/src/Hash2Pub/PostService.hs
index 69f1b13..bd83506 100644
--- a/src/Hash2Pub/PostService.hs
+++ b/src/Hash2Pub/PostService.hs
@@ -100,6 +100,7 @@ instance DHT d => Service PostService d where
         statsQueue' <- newTQueueIO
         loadStats' <- newTVarIO emptyStats
         loggingFile <- openFile (confLogfilePath conf) WriteMode
+        hSetBuffering loggingFile LineBuffering
         let
             thisService = PostService
               { serviceConf = conf
@@ -121,7 +122,7 @@ instance DHT d => Service PostService d where
         -- log a start message, this also truncates existing files
         TxtI.hPutStrLn loggingFile $ Txt.unlines
             [ "# Starting mock relay implementation"
-            , "#relay receive rate   ;relay delivery rate   ;instance publish rate ;instance fetch rate   ;total subscriptions"
+            , "#time stamp         ; relay receive rate   ;relay delivery rate   ;instance publish rate ;instance fetch rate   ;total subscriptions"
             ]
         -- Run 'concurrently_' from another thread to be able to return the
         -- 'PostService'.
@@ -841,7 +842,8 @@ evaluateStatsThread serv statsAcc = getPOSIXTime >>= loop
           -- later: current (reported) load, target load
           subscriberSum <- sumSubscribers
           TxtI.hPutStrLn (logFileHandle serv) $
-              format (fixed 20 % ";" % fixed 20 % ";" % fixed 20 % ";" % fixed 20 % ";" % int )
+              format (fixed 9 % ";" % fixed 20 % ";" % fixed 20 % ";" % fixed 20 % ";" % fixed 20 % ";" % int )
+                  (realToFrac now :: Double)
                   (sum . relayReceiveRates $ rateStats)
                   (sum . relayDeliveryRates $ rateStats)
                   (postPublishRate rateStats)