diff --git a/src/Data/Time/Exts/Local.hs b/src/Data/Time/Exts/Local.hs
--- a/src/Data/Time/Exts/Local.hs
+++ b/src/Data/Time/Exts/Local.hs
@@ -46,6 +46,7 @@
  -- ** Time Zone Transition Times
      , Transition(..)
      , getTransitions
+     , lastTransition
 
  -- ** Get Current Local Timestamps Using Preloaded Time Zone Transitions Times
      , getCurrentLocalDate'
@@ -886,10 +887,10 @@
    let file = getOlsonFile city
    Olson.OlsonData{..} <- Olson.getOlsonFromFile file
    let ttimes = uniquetimes $ sortBy future2past olsonTransitions
-   return $! foldr (step olsonTypes) [] ttimes
+   return $! foldr (step olsonTypes) [] $ map last ttimes
    where uniquetimes = groupBy $ on (==) Olson.transTime
          future2past = comparing $ negate . Olson.transTime
-         step types ~[Olson.Transition{..}] accum =
+         step types Olson.Transition{..} accum =
            if transTime < 0
            then [Transition (LocalDateTime 43200 zone)]
            else  Transition (LocalDateTime  base zone) : accum
@@ -898,6 +899,14 @@
                  base = baseUnixToUTC $ fromIntegral transTime
                  zone = fromZone $ unabbreviate abbr
 
+-- | Get the last time zone transition time for the given city and time.
+lastTransition :: (DateTime dt, Unix dt) => City -> dt -> IO (Maybe Transition)
+lastTransition city time = do
+   ttimes <- getTransitions city
+   return $! listToMaybe $ dropWhile f ttimes
+   where base = baseUnixToUTC $ unixNorm time
+         f tt = localBase tt > base
+
 -- | Get the current local date from the system clock.
 --
 -- > >>> getCurrentLocalDate London 
@@ -1049,7 +1058,7 @@
 -- > >>> getCurrentLocalDateTimePicos Karachi
 -- > 2013-11-04 22:05:17.556043000000 PKT
 --
---   Note that this functions calls @gettimeofday()@ behind the scenes. Therefore, the resultant
+--   Note that this functions calls @gettimeofday@ behind the scenes. Therefore, the resultant
 --   timestamp will have picosecond granularity, but only microsecond resolution.
 getCurrentLocalDateTimePicos :: City -> IO LocalDateTimePicos
 getCurrentLocalDateTimePicos city = getTransitions city >>= getCurrentLocalDateTimePicos'
@@ -1065,7 +1074,7 @@
 --   granularity more than once. The use of preloaded transition times will avoid unnecessary
 --   parsing of Olson files.
 --
---   Note that this functions calls @gettimeofday()@ behind the scenes. Therefore, the resultant
+--   Note that this functions calls @gettimeofday@ behind the scenes. Therefore, the resultant
 --   timestamp will have picosecond granularity, but only microsecond resolution.
 getCurrentLocalDateTimePicos' :: [Transition] -> IO LocalDateTimePicos
 getCurrentLocalDateTimePicos' ttimes = do
diff --git a/src/Data/Time/Exts/Unix.hs b/src/Data/Time/Exts/Unix.hs
--- a/src/Data/Time/Exts/Unix.hs
+++ b/src/Data/Time/Exts/Unix.hs
@@ -71,6 +71,9 @@
     -- | Get the base component of a Unix timestamp.
     unixBase :: u -> Int64
 
+    -- | Get the normalized base component of a Unix timestamp.
+    unixNorm :: u -> Int64
+
 -- | Days since Unix epoch.
 newtype UnixDate = UnixDate {
     _uni_day_base :: Int32
@@ -173,21 +176,27 @@
 
 instance Unix UnixDate where
     unixBase = fromIntegral . get uni_day_base
+    unixNorm = unixBase
 
 instance Unix UnixDateTime where
     unixBase = get uni_sec_base
+    unixNorm = unixBase
 
 instance Unix UnixDateTimeMillis where
     unixBase = get uni_mil_base
+    unixNorm = flip div 1000 . unixBase
 
 instance Unix UnixDateTimeMicros where
     unixBase = get uni_mic_base
+    unixNorm = flip div 1000000 . unixBase
 
 instance Unix UnixDateTimeNanos where
     unixBase = get uni_nan_base
+    unixNorm = flip div 1000000 . unixBase
 
 instance Unix UnixDateTimePicos where
     unixBase = get uni_pic_base
+    unixNorm = flip div 1000000 . unixBase
 
 instance DateTimeMath UnixDate Day where
     date `plus` Day day =
diff --git a/time-exts.cabal b/time-exts.cabal
--- a/time-exts.cabal
+++ b/time-exts.cabal
@@ -1,5 +1,5 @@
 Name:               time-exts
-Version:            1.1.2
+Version:            1.1.3
 License:            BSD3
 License-File:       LICENSE
 Copyright:          Copyright (c) 2014, Enzo Haussecker. All rights reserved.