diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Changelog for interval-algebra
 
+## 1.1.3
+
+* `Arbitrary` instances for `DiffTime`, `NominalDiffTime` and `Day` are now sized, the absence of which had prevented the 'fix' from version 1.1.1 from being effective. `DiffTime` and `NominalDiffTime` generators are also now limited to a maximum `86399` seconds directly.
+
 ## 1.1.2
 
 * Adds an internal utility to `IntervalAlgebra.Arbitrary` to generate a `Maybe (i a)` for `Intervallic i a` from a reference interval and set of relations. `Nothing` is returned for cases in which no interval can be generated.
diff --git a/interval-algebra.cabal b/interval-algebra.cabal
--- a/interval-algebra.cabal
+++ b/interval-algebra.cabal
@@ -1,6 +1,6 @@
 cabal-version:  2.2
 name:           interval-algebra
-version:        1.1.2
+version:        1.1.3
 synopsis:       An implementation of Allen's interval algebra for temporal logic
 description:    Please see the README on GitHub at <https://github.com/novisci/interval-algebra>
 category:       Algebra,Time
diff --git a/src/IntervalAlgebra/Arbitrary.hs b/src/IntervalAlgebra/Arbitrary.hs
--- a/src/IntervalAlgebra/Arbitrary.hs
+++ b/src/IntervalAlgebra/Arbitrary.hs
@@ -38,32 +38,32 @@
 import           Prelude             (Eq, (==))
 import           Test.QuickCheck     (Arbitrary (arbitrary, shrink), Gen,
                                       NonNegative, arbitrarySizedNatural,
-                                      elements, resize, suchThat)
+                                      elements, resize, suchThat, sized)
 
 -- NOTE: the default size for arbitrary :: Gen Int appears to be 30
 arbitrarySizedPositive :: Integral a => Gen a
 arbitrarySizedPositive = (+ 1) <$> arbitrarySizedNatural
 
+-- resize in utctDayTime is to avoid rare leap-seconds-related failure, in
+-- which e.g.  1858-12-31 00:00:00 UTC /= 1858-12-30 23:59:60 UTC
 maxDiffTime :: Int
-maxDiffTime = 86400
+maxDiffTime = 86399
 
 instance Arbitrary (Interval Int) where
   arbitrary = liftM2 beginerval arbitrarySizedPositive arbitrary
 
 instance Arbitrary DT.Day where
-    arbitrary = DT.ModifiedJulianDay <$> arbitrary
+    arbitrary = sized (\s -> DT.ModifiedJulianDay <$> s `resize` arbitrary)
     shrink    = (DT.ModifiedJulianDay <$>) . shrink . DT.toModifiedJulianDay
 
 instance Arbitrary DT.NominalDiffTime where
-   arbitrary = fromInteger <$> (maxDiffTime `resize` arbitrarySizedNatural)
+   arbitrary = sized (\s -> fromInteger <$> (min s maxDiffTime `resize` arbitrarySizedNatural))
 
 instance Arbitrary DT.DiffTime where
-   arbitrary = fromInteger <$> (maxDiffTime `resize` arbitrarySizedNatural)
+   arbitrary = sized (\s -> fromInteger <$> (min s maxDiffTime `resize` arbitrarySizedNatural))
 
 instance Arbitrary DT.UTCTime  where
-    -- resize in utctDayTime is to avoid rare leap-seconds-related failure, in
-    -- which e.g.  1858-12-31 00:00:00 UTC /= 1858-12-30 23:59:60 UTC
-    arbitrary = liftA2 UTCTime arbitrary (86399 `resize` arbitrary)
+    arbitrary = liftA2 UTCTime arbitrary arbitrary
                   
 instance Arbitrary (Interval DT.Day) where
   arbitrary = liftM2 beginerval arbitrary arbitrary