chore(status): improve readability of time spans

src/Handler/Health.hs

@@ -6,6 +6,7 @@ module Handler.Health where
 
 import Import
 
+import Data.Time.Format.ISO8601 (iso8601Show)
 import Handler.Utils.DateTime (formatTimeW)
 
 import qualified Data.Aeson.Encode.Pretty as Aeson
@@ -115,6 +116,8 @@ getStatusR = do
   starttime <- getsYesod appStartTime
   (currtime, env_version) <- liftIO $ (,) <$> getCurrentTime <*> lookupEnv "VERSION_NR"
   -- ft <- formatTime'  "%Y-%m-%d %H:%M:%S" currtime
+  let diffTime :: UTCTime -> Text
+      diffTime = pack . iso8601Show . calendarTimeTime . fromIntegral . truncate . diffUTCTime currtime
   withUrlRenderer
     [hamlet|
       $doctype 5
@@ -131,16 +134,13 @@ getStatusR = do
           <p>
             Instance Start <br>
             #{show starttime} #
-            Uptime: #{show $ ddays starttime currtime} days.
+            Uptime: #{diffTime starttime}
           <p>
             Compile Time <br>
             #{show cTime} #
-            Build age: #{show $ ddays cTime currtime} days.
+            Build age: #{diffTime cTime}
     |]
   where
     -- vnr_full :: Text = $(embedStringFile "nix/docker/version.json") -- nix/ files not accessible during container construction
     cTime :: UTCTime
     cTime = $compileTime
-
-    ddays :: UTCTime -> UTCTime -> Double
-    ddays tstart tstop = (/100) $ fromIntegral $ round $ diffUTCTime tstop tstart / (36 * 24)