diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,12 @@
 # Change Log
 
+## [1.16] - 2026-05-03
+
+- add periodIn
+- use template-haskell-lift rather than template-haskell for Lift instances on GHC 9.14 and later
+- support GHC 9.14
+- improve documentation, test, build, CI
+
 ## [1.15] - 2025-08-04
 
 - support compiler / GHC backends (with CI):
@@ -18,6 +25,7 @@
   - loosen up parsing time-zone modifiers
 - add Lift instances to all types (really this time)
 - hide Data.Time.Format.Internal
+- add periodToDayClip
 - fix MonthDay and QuarterDay clipping
 
 ## [1.14] - 2024-03-10
diff --git a/configure b/configure
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.71 for Haskell time package 1.15.
+# Generated by GNU Autoconf 2.71 for Haskell time package 1.16.
 #
 # Report bugs to <ashley@semantic.org>.
 #
@@ -610,8 +610,8 @@
 # Identity of this package.
 PACKAGE_NAME='Haskell time package'
 PACKAGE_TARNAME='time'
-PACKAGE_VERSION='1.15'
-PACKAGE_STRING='Haskell time package 1.15'
+PACKAGE_VERSION='1.16'
+PACKAGE_STRING='Haskell time package 1.16'
 PACKAGE_BUGREPORT='ashley@semantic.org'
 PACKAGE_URL=''
 
@@ -1258,7 +1258,7 @@
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures Haskell time package 1.15 to adapt to many kinds of systems.
+\`configure' configures Haskell time package 1.16 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1320,7 +1320,7 @@
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of Haskell time package 1.15:";;
+     short | recursive ) echo "Configuration of Haskell time package 1.16:";;
    esac
   cat <<\_ACEOF
 
@@ -1406,7 +1406,7 @@
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-Haskell time package configure 1.15
+Haskell time package configure 1.16
 generated by GNU Autoconf 2.71
 
 Copyright (C) 2021 Free Software Foundation, Inc.
@@ -1736,7 +1736,7 @@
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by Haskell time package $as_me 1.15, which was
+It was created by Haskell time package $as_me 1.16, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -4334,7 +4334,7 @@
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by Haskell time package $as_me 1.15, which was
+This file was extended by Haskell time package $as_me 1.16, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -4389,7 +4389,7 @@
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
-Haskell time package config.status 1.15
+Haskell time package config.status 1.16
 configured by $0, generated by GNU Autoconf 2.71,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([Haskell time package],[1.15],[ashley@semantic.org],[time])
+AC_INIT([Haskell time package],[1.16],[ashley@semantic.org],[time])
 
 # Safety check: Ensure that we are in the correct source directory.
 AC_CONFIG_SRCDIR([lib/include/HsTime.h])
diff --git a/lib/Data/Time/Calendar.hs b/lib/Data/Time/Calendar.hs
--- a/lib/Data/Time/Calendar.hs
+++ b/lib/Data/Time/Calendar.hs
@@ -9,6 +9,7 @@
     -- * DayPeriod
     DayPeriod (..),
     periodAllDays,
+    periodIn,
     periodLength,
     periodFromDay,
     periodToDay,
diff --git a/lib/Data/Time/Calendar/CalendarDiffDays.hs b/lib/Data/Time/Calendar/CalendarDiffDays.hs
--- a/lib/Data/Time/Calendar/CalendarDiffDays.hs
+++ b/lib/Data/Time/Calendar/CalendarDiffDays.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.Calendar.CalendarDiffDays where
@@ -5,7 +6,11 @@
 import Control.DeepSeq
 import Data.Data
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 data CalendarDiffDays = CalendarDiffDays
     { cdMonths :: Integer
diff --git a/lib/Data/Time/Calendar/Days.hs b/lib/Data/Time/Calendar/Days.hs
--- a/lib/Data/Time/Calendar/Days.hs
+++ b/lib/Data/Time/Calendar/Days.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.Calendar.Days where
@@ -7,7 +8,11 @@
 import Data.Ix
 import Data.Time.Calendar.Private
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | The Modified Julian Day is a standard count of days, with zero being the day 1858-11-17.
 newtype Day = ModifiedJulianDay
@@ -60,6 +65,12 @@
 periodAllDays :: DayPeriod p => p -> [Day]
 periodAllDays p = [periodFirstDay p .. periodLastDay p]
 
+-- | Test whether a day is in a given period.
+--
+-- @since 1.16
+periodIn :: DayPeriod p => p -> Day -> Bool
+periodIn p d = (d >= periodFirstDay p) && (d <= periodLastDay p)
+
 -- | The number of days in this period.
 --
 -- @since 1.12.1
@@ -85,6 +96,9 @@
 periodToDay :: DayPeriod p => p -> Int -> Day
 periodToDay p i = addDays (toInteger $ pred i) $ periodFirstDay p
 
+-- | Inverse of 'periodFromDay', clipping the day number to the period.
+--
+-- @since 1.15
 periodToDayClip :: DayPeriod p => p -> Int -> Day
 periodToDayClip p i = periodToDay p $ clip 1 (periodLength p) i
 
diff --git a/lib/Data/Time/Calendar/Gregorian.hs b/lib/Data/Time/Calendar/Gregorian.hs
--- a/lib/Data/Time/Calendar/Gregorian.hs
+++ b/lib/Data/Time/Calendar/Gregorian.hs
@@ -90,7 +90,9 @@
 addGregorianDurationRollOver :: CalendarDiffDays -> Day -> Day
 addGregorianDurationRollOver (CalendarDiffDays m d) day = addDays d $ addGregorianMonthsRollOver m day
 
--- | Calendrical difference, with as many whole months as possible
+-- | Calendrical difference, with as many whole months as possible.
+-- Has the property @addGregorianDurationClip (diffGregorianDurationClip d2 d1) d1 = d2@.
+-- For example, 2027-03-01 - 2027-01-31 = 1 month and 1 day.
 diffGregorianDurationClip :: Day -> Day -> CalendarDiffDays
 diffGregorianDurationClip day2 day1 =
     let
@@ -114,6 +116,8 @@
         CalendarDiffDays ymAllowed $ diffDays day2 dayAllowed
 
 -- | Calendrical difference, with as many whole months as possible.
+-- Has the property @addGregorianDurationRollOver (diffGregorianDurationRollOver d2 d1) d1 = d2@.
+-- For example, 2027-03-01 - 2027-01-31 = 29 days.
 diffGregorianDurationRollOver :: Day -> Day -> CalendarDiffDays
 diffGregorianDurationRollOver day2 day1 =
     let
diff --git a/lib/Data/Time/Calendar/Month.hs b/lib/Data/Time/Calendar/Month.hs
--- a/lib/Data/Time/Calendar/Month.hs
+++ b/lib/Data/Time/Calendar/Month.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -- | An absolute count of common calendar months.
@@ -20,7 +21,11 @@
 import Data.Time.Calendar.Private
 import Data.Time.Calendar.Types
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 import Text.ParserCombinators.ReadP
 import Text.Read
 
diff --git a/lib/Data/Time/Calendar/Quarter.hs b/lib/Data/Time/Calendar/Quarter.hs
--- a/lib/Data/Time/Calendar/Quarter.hs
+++ b/lib/Data/Time/Calendar/Quarter.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -- | Year quarters.
@@ -23,7 +24,11 @@
 import Data.Time.Calendar.Private
 import Data.Time.Calendar.Types
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 import Text.ParserCombinators.ReadP
 import Text.Read
 
diff --git a/lib/Data/Time/Calendar/Week.hs b/lib/Data/Time/Calendar/Week.hs
--- a/lib/Data/Time/Calendar/Week.hs
+++ b/lib/Data/Time/Calendar/Week.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.Calendar.Week where
@@ -8,7 +9,11 @@
 import Data.Ix
 import Data.Time.Calendar.Days
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 data DayOfWeek
     = Monday
diff --git a/lib/Data/Time/Calendar/WeekDate.hs b/lib/Data/Time/Calendar/WeekDate.hs
--- a/lib/Data/Time/Calendar/WeekDate.hs
+++ b/lib/Data/Time/Calendar/WeekDate.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -- | Week-based calendars
@@ -23,7 +24,11 @@
 import Data.Time.Calendar.OrdinalDate
 import Data.Time.Calendar.Private
 import Data.Time.Calendar.Week
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 data FirstWeekType
     = -- | first week is the first whole week of the year
diff --git a/lib/Data/Time/Clock/Internal/AbsoluteTime.hs b/lib/Data/Time/Clock/Internal/AbsoluteTime.hs
--- a/lib/Data/Time/Clock/Internal/AbsoluteTime.hs
+++ b/lib/Data/Time/Clock/Internal/AbsoluteTime.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 -- | TAI and leap-second maps for converting to UTC: most people won't need this module.
@@ -7,7 +8,11 @@
 import Data.Data
 import Data.Time.Calendar.Days
 import Data.Time.Clock.Internal.DiffTime
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | AbsoluteTime is TAI, time as measured by a clock.
 newtype AbsoluteTime
diff --git a/lib/Data/Time/Clock/Internal/DiffTime.hs b/lib/Data/Time/Clock/Internal/DiffTime.hs
--- a/lib/Data/Time/Clock/Internal/DiffTime.hs
+++ b/lib/Data/Time/Clock/Internal/DiffTime.hs
@@ -9,7 +9,11 @@
 #ifdef __GLASGOW_HASKELL__
 import GHC.Read
 #endif
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 import Text.ParserCombinators.ReadP
 import Text.Read
 
diff --git a/lib/Data/Time/Clock/Internal/NominalDiffTime.hs b/lib/Data/Time/Clock/Internal/NominalDiffTime.hs
--- a/lib/Data/Time/Clock/Internal/NominalDiffTime.hs
+++ b/lib/Data/Time/Clock/Internal/NominalDiffTime.hs
@@ -10,7 +10,11 @@
 import GHC.Read
 #endif
 import Data.Time.Clock.Internal.DiffTime
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 import Text.ParserCombinators.ReadP
 import Text.ParserCombinators.ReadPrec
 
diff --git a/lib/Data/Time/Clock/Internal/SystemTime.hs b/lib/Data/Time/Clock/Internal/SystemTime.hs
--- a/lib/Data/Time/Clock/Internal/SystemTime.hs
+++ b/lib/Data/Time/Clock/Internal/SystemTime.hs
@@ -23,7 +23,11 @@
 import Data.Time.Clock.Internal.DiffTime
 import Data.Word
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 #ifdef mingw32_HOST_OS
 import qualified System.Win32.Time as Win32
diff --git a/lib/Data/Time/Clock/Internal/UTCTime.hs b/lib/Data/Time/Clock/Internal/UTCTime.hs
--- a/lib/Data/Time/Clock/Internal/UTCTime.hs
+++ b/lib/Data/Time/Clock/Internal/UTCTime.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.Clock.Internal.UTCTime where
@@ -7,7 +8,11 @@
 import Data.Time.Calendar.Days
 import Data.Time.Clock.Internal.DiffTime
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | This is the simplest representation of UTC.
 -- It consists of the day number, and a time offset from midnight.
diff --git a/lib/Data/Time/Clock/Internal/UniversalTime.hs b/lib/Data/Time/Clock/Internal/UniversalTime.hs
--- a/lib/Data/Time/Clock/Internal/UniversalTime.hs
+++ b/lib/Data/Time/Clock/Internal/UniversalTime.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.Clock.Internal.UniversalTime where
@@ -5,7 +6,11 @@
 import Control.DeepSeq
 import Data.Data
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | The Modified Julian Date is the day with the fraction of the day, measured from UT midnight.
 -- It's used to represent UT1, which is time as measured by the earth's rotation, adjusted for various wobbles.
diff --git a/lib/Data/Time/LocalTime/Internal/CalendarDiffTime.hs b/lib/Data/Time/LocalTime/Internal/CalendarDiffTime.hs
--- a/lib/Data/Time/LocalTime/Internal/CalendarDiffTime.hs
+++ b/lib/Data/Time/LocalTime/Internal/CalendarDiffTime.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.LocalTime.Internal.CalendarDiffTime where
@@ -10,7 +11,11 @@
 import Data.Time.Clock.Internal.UTCDiff
 import Data.Time.Clock.Internal.UTCTime
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 data CalendarDiffTime = CalendarDiffTime
     { ctMonths :: Integer
diff --git a/lib/Data/Time/LocalTime/Internal/LocalTime.hs b/lib/Data/Time/LocalTime/Internal/LocalTime.hs
--- a/lib/Data/Time/LocalTime/Internal/LocalTime.hs
+++ b/lib/Data/Time/LocalTime/Internal/LocalTime.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 {-# OPTIONS -fno-warn-orphans #-}
@@ -16,7 +17,11 @@
 import Data.Time.LocalTime.Internal.TimeOfDay
 import Data.Time.LocalTime.Internal.TimeZone
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | A simple day and time aggregate, where the day is of the specified parameter,
 -- and the time is a TimeOfDay.
diff --git a/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs b/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs
--- a/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs
+++ b/lib/Data/Time/LocalTime/Internal/TimeOfDay.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.LocalTime.Internal.TimeOfDay where
@@ -10,7 +11,11 @@
 import Data.Time.Clock.Internal.NominalDiffTime
 import Data.Time.LocalTime.Internal.TimeZone
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | Time of day as represented in hour, minute and second (with picoseconds), typically used to express local time of day.
 --
diff --git a/lib/Data/Time/LocalTime/Internal/TimeZone.hs b/lib/Data/Time/LocalTime/Internal/TimeZone.hs
--- a/lib/Data/Time/LocalTime/Internal/TimeZone.hs
+++ b/lib/Data/Time/LocalTime/Internal/TimeZone.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 module Data.Time.LocalTime.Internal.TimeZone (
@@ -15,7 +16,11 @@
 import Data.Data
 import Data.Time.Calendar.Private
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | A TimeZone is a whole number of minutes offset from UTC, together with a name and a \"just for summer\" flag.
 data TimeZone = TimeZone
diff --git a/lib/Data/Time/LocalTime/Internal/ZonedTime.hs b/lib/Data/Time/LocalTime/Internal/ZonedTime.hs
--- a/lib/Data/Time/LocalTime/Internal/ZonedTime.hs
+++ b/lib/Data/Time/LocalTime/Internal/ZonedTime.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 
 {-# OPTIONS -fno-warn-orphans #-}
@@ -12,7 +13,11 @@
 import Data.Time.LocalTime.Internal.LocalTime
 import Data.Time.LocalTime.Internal.TimeZone
 import GHC.Generics
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 
 -- | A local time together with a time zone.
 --
diff --git a/test/main/Test/AddDiff.hs b/test/main/Test/AddDiff.hs
new file mode 100644
--- /dev/null
+++ b/test/main/Test/AddDiff.hs
@@ -0,0 +1,20 @@
+module Test.AddDiff (
+    AddDiff (..),
+    testAddDiff,
+) where
+
+import Test.Arbitrary
+import Test.Tasty
+import Test.Tasty.QuickCheck hiding (reason)
+
+data AddDiff duration time = MkAddDiff
+    { adName :: String
+    , adAdd :: duration -> time -> time
+    , adDifference :: time -> time -> duration
+    }
+
+testAddDiff :: (Arbitrary (NoLeapSeconds time), Eq time, Show time) => AddDiff duration time -> TestTree
+testAddDiff MkAddDiff{..} =
+    testProperty adName $
+        \(MkNoLeapSeconds time1) (MkNoLeapSeconds time2) ->
+            adAdd (adDifference time2 time1) time1 == time2
diff --git a/test/main/Test/Arbitrary.hs b/test/main/Test/Arbitrary.hs
--- a/test/main/Test/Arbitrary.hs
+++ b/test/main/Test/Arbitrary.hs
@@ -1,6 +1,9 @@
 {-# OPTIONS -fno-warn-orphans #-}
 
-module Test.Arbitrary (supportedDayRange) where
+module Test.Arbitrary (
+    supportedDayRange,
+    NoLeapSeconds (..),
+) where
 
 import Control.Monad
 import Data.Fixed
@@ -96,6 +99,16 @@
 instance Arbitrary CalendarDiffDays where
     arbitrary = liftM2 CalendarDiffDays arbitrary arbitrary
 
+newtype NoLeapSeconds a = MkNoLeapSeconds {unNoLeapSeconds :: a}
+    deriving newtype (Eq, Ord, Show)
+
+arbitraryNoLeapSeconds :: Arbitrary (NoLeapSeconds a) => Gen a
+arbitraryNoLeapSeconds = fmap unNoLeapSeconds arbitrary
+
+instance {-# OVERLAPPABLE #-} Arbitrary t => Arbitrary (NoLeapSeconds t) where
+    arbitrary = fmap MkNoLeapSeconds arbitrary
+    shrink (MkNoLeapSeconds t) = fmap MkNoLeapSeconds $ shrink t
+
 instance Arbitrary DiffTime where
     arbitrary = oneof [intSecs, fracSecs] -- up to 1 leap second
       where
@@ -109,6 +122,17 @@
 instance CoArbitrary DiffTime where
     coarbitrary t = coarbitrary (fromEnum t)
 
+instance Arbitrary (NoLeapSeconds DiffTime) where
+    arbitrary = fmap MkNoLeapSeconds $ oneof [intSecs, fracSecs] -- no leap second
+      where
+        intSecs = liftM secondsToDiffTime' $ choose (0, 86399)
+        fracSecs = liftM picosecondsToDiffTime' $ choose (0, 86399 * 10 ^ (12 :: Int))
+        secondsToDiffTime' :: Integer -> DiffTime
+        secondsToDiffTime' = fromInteger
+        picosecondsToDiffTime' :: Integer -> DiffTime
+        picosecondsToDiffTime' x = fromRational (x % 10 ^ (12 :: Int))
+    shrink (MkNoLeapSeconds t) = fmap MkNoLeapSeconds $ shrink t
+
 instance Arbitrary NominalDiffTime where
     arbitrary = oneof [intSecs, fracSecs]
       where
@@ -156,6 +180,10 @@
                 ++ [TimeOfDay h m' s | m' <- shrinkInt m]
                 ++ [TimeOfDay h m s' | s' <- shrinkPico s]
 
+instance Arbitrary (NoLeapSeconds TimeOfDay) where
+    arbitrary = fmap (MkNoLeapSeconds . timeToTimeOfDay) arbitraryNoLeapSeconds
+    shrink (MkNoLeapSeconds t) = fmap MkNoLeapSeconds $ shrink t
+
 instance CoArbitrary TimeOfDay where
     coarbitrary t = coarbitrary (timeOfDayToTime t)
 
@@ -166,6 +194,10 @@
 instance CoArbitrary LocalTime where
     coarbitrary t = coarbitrary (floor (utcTimeToPOSIXSeconds (localTimeToUTC utc t)) :: Integer)
 
+instance Arbitrary (NoLeapSeconds LocalTime) where
+    arbitrary = fmap MkNoLeapSeconds $ liftM2 LocalTime arbitraryNoLeapSeconds arbitraryNoLeapSeconds
+    shrink (MkNoLeapSeconds t) = fmap MkNoLeapSeconds $ shrink t
+
 instance Arbitrary TimeZone where
     arbitrary = liftM minutesToTimeZone $ choose (-720, 720)
     shrink (TimeZone 0 _ _) = []
@@ -181,12 +213,20 @@
 instance CoArbitrary ZonedTime where
     coarbitrary t = coarbitrary (floor (utcTimeToPOSIXSeconds (zonedTimeToUTC t)) :: Integer)
 
+instance Arbitrary (NoLeapSeconds ZonedTime) where
+    arbitrary = fmap MkNoLeapSeconds $ liftM2 ZonedTime arbitraryNoLeapSeconds arbitraryNoLeapSeconds
+    shrink (MkNoLeapSeconds t) = fmap MkNoLeapSeconds $ shrink t
+
 instance Arbitrary UTCTime where
     arbitrary = liftM2 UTCTime arbitrary arbitrary
     shrink t = fmap (localTimeToUTC utc) $ shrink $ utcToLocalTime utc t
 
 instance CoArbitrary UTCTime where
     coarbitrary t = coarbitrary (floor (utcTimeToPOSIXSeconds t) :: Integer)
+
+instance Arbitrary (NoLeapSeconds UTCTime) where
+    arbitrary = fmap MkNoLeapSeconds $ liftM2 UTCTime arbitraryNoLeapSeconds arbitraryNoLeapSeconds
+    shrink (MkNoLeapSeconds t) = fmap MkNoLeapSeconds $ shrink t
 
 instance Arbitrary UniversalTime where
     arbitrary = liftM (\n -> ModJulianDate $ n % k) $ choose (-313698 * k, 2973483 * k) -- 1000-01-1 to 9999-12-31
diff --git a/test/main/Test/Calendar/Duration.hs b/test/main/Test/Calendar/Duration.hs
--- a/test/main/Test/Calendar/Duration.hs
+++ b/test/main/Test/Calendar/Duration.hs
@@ -4,31 +4,27 @@
 
 import Data.Time.Calendar
 import Data.Time.Calendar.Julian
+import Test.AddDiff
 import Test.Arbitrary ()
 import Test.Tasty
 import Test.Tasty.HUnit
 import Test.Tasty.QuickCheck hiding (reason)
 
-data AddDiff = MkAddDiff
-    { adName :: String
-    , adAdd :: CalendarDiffDays -> Day -> Day
-    , adDifference :: Day -> Day -> CalendarDiffDays
-    , adFromYMD :: Integer -> Int -> Int -> Day
-    }
+type CalendarAddDiff = (AddDiff CalendarDiffDays Day, Integer -> Int -> Int -> Day)
 
-gregorianClip :: AddDiff
-gregorianClip = MkAddDiff "gregorianClip" addGregorianDurationClip diffGregorianDurationClip fromGregorian
+gregorianClip :: CalendarAddDiff
+gregorianClip = (MkAddDiff "gregorianClip" addGregorianDurationClip diffGregorianDurationClip, fromGregorian)
 
-gregorianRollOver :: AddDiff
-gregorianRollOver = MkAddDiff "gregorianRollOver" addGregorianDurationRollOver diffGregorianDurationRollOver fromGregorian
+gregorianRollOver :: CalendarAddDiff
+gregorianRollOver = (MkAddDiff "gregorianRollOver" addGregorianDurationRollOver diffGregorianDurationRollOver, fromGregorian)
 
-julianClip :: AddDiff
-julianClip = MkAddDiff "julianClip" addJulianDurationClip diffJulianDurationClip fromJulian
+julianClip :: CalendarAddDiff
+julianClip = (MkAddDiff "julianClip" addJulianDurationClip diffJulianDurationClip, fromJulian)
 
-julianRollOver :: AddDiff
-julianRollOver = MkAddDiff "julianRollOver" addJulianDurationRollOver diffJulianDurationRollOver fromJulian
+julianRollOver :: CalendarAddDiff
+julianRollOver = (MkAddDiff "julianRollOver" addJulianDurationRollOver diffJulianDurationRollOver, fromJulian)
 
-addDiffs :: [AddDiff]
+addDiffs :: [CalendarAddDiff]
 addDiffs =
     [ gregorianClip
     , gregorianRollOver
@@ -36,15 +32,11 @@
     , julianRollOver
     ]
 
-testAddDiff :: AddDiff -> TestTree
-testAddDiff MkAddDiff{..} = testProperty adName $ \day1 day2 ->
-    adAdd (adDifference day2 day1) day1 == day2
-
 testAddDiffs :: TestTree
 testAddDiffs =
     testGroup
         "add-diff"
-        $ fmap testAddDiff addDiffs
+        $ fmap (testAddDiff . fst) addDiffs
 
 newtype Smallish = MkSmallish Integer deriving (Eq, Ord)
 
@@ -56,8 +48,8 @@
         n <- if b then choose (0, 60) else return 30
         return $ MkSmallish n
 
-testPositiveDiff :: AddDiff -> TestTree
-testPositiveDiff MkAddDiff{..} = testProperty adName $ \day1 (MkSmallish i) ->
+testPositiveDiff :: CalendarAddDiff -> TestTree
+testPositiveDiff (MkAddDiff{..}, _) = testProperty adName $ \day1 (MkSmallish i) ->
     let
         day2 = addDays i day1
         r = adDifference day2 day1
@@ -70,11 +62,11 @@
         "positive-diff"
         $ fmap testPositiveDiff addDiffs
 
-testSpecific :: AddDiff -> (Integer, Int, Int) -> (Integer, Int, Int) -> (Integer, Integer) -> TestTree
-testSpecific MkAddDiff{..} (y2, m2, d2) (y1, m1, d1) (em, ed) =
+testSpecific :: CalendarAddDiff -> (Integer, Int, Int) -> (Integer, Int, Int) -> (Integer, Integer) -> TestTree
+testSpecific (MkAddDiff{..}, fromYMD) (y2, m2, d2) (y1, m1, d1) (em, ed) =
     let
-        day1 = adFromYMD y1 m1 d1
-        day2 = adFromYMD y2 m2 d2
+        day1 = fromYMD y1 m1 d1
+        day2 = fromYMD y2 m2 d2
         expected = CalendarDiffDays em ed
         found = adDifference day2 day1
     in
diff --git a/test/main/Test/LocalTime/CalendarDiffTime.hs b/test/main/Test/LocalTime/CalendarDiffTime.hs
--- a/test/main/Test/LocalTime/CalendarDiffTime.hs
+++ b/test/main/Test/LocalTime/CalendarDiffTime.hs
@@ -2,12 +2,97 @@
     testCalendarDiffTime,
 ) where
 
+import Data.Fixed
 import Data.Time
+import Test.AddDiff
 import Test.Arbitrary ()
 import Test.Tasty
 import Test.Tasty.HUnit
 import Test.TestUtil
 
+utcClip :: AddDiff CalendarDiffTime UTCTime
+utcClip = MkAddDiff "utcClip" addUTCDurationClip diffUTCDurationClip
+
+utcRollOver :: AddDiff CalendarDiffTime UTCTime
+utcRollOver = MkAddDiff "utcRollOver" addUTCDurationRollOver diffUTCDurationRollOver
+
+localClip :: AddDiff CalendarDiffTime LocalTime
+localClip = MkAddDiff "localClip" addLocalDurationClip diffLocalDurationClip
+
+localRollOver :: AddDiff CalendarDiffTime LocalTime
+localRollOver = MkAddDiff "localRollOver" addLocalDurationRollOver diffLocalDurationRollOver
+
+testAddDiffs :: TestTree
+testAddDiffs =
+    testGroup
+        "add-diff"
+        [ testGroup "UTC" $ fmap testAddDiff [utcClip, utcRollOver]
+        , testGroup "LocalTime" $ fmap testAddDiff [localClip, localRollOver]
+        ]
+
+utcTime :: Integer -> Int -> Int -> DiffTime -> UTCTime
+utcTime y m d = UTCTime (YearMonthDay y m d)
+
+localTime :: Integer -> Int -> Int -> Int -> Int -> Pico -> LocalTime
+localTime y m d h minute s = LocalTime (YearMonthDay y m d) $ TimeOfDay h minute s
+
+testSpecifics :: TestTree
+testSpecifics =
+    testGroup
+        "specific"
+        [ testGroup
+            "add"
+            [ testCase "UTC clip" $
+                assertEqual
+                    "Jan 31 + 1 month clips to Feb 28"
+                    (utcTime 2001 2 28 0)
+                    (addUTCDurationClip (CalendarDiffTime 1 0) $ utcTime 2001 1 31 0)
+            , testCase "UTC rollover" $
+                assertEqual
+                    "Jan 31 + 1 month rolls over to Mar 3"
+                    (utcTime 2001 3 3 0)
+                    (addUTCDurationRollOver (CalendarDiffTime 1 0) $ utcTime 2001 1 31 0)
+            , testCase "LocalTime clip" $
+                assertEqual
+                    "Jan 31 + 1 month clips to Feb 28"
+                    (localTime 2001 2 28 0 0 0)
+                    (addLocalDurationClip (CalendarDiffTime 1 0) $ localTime 2001 1 31 0 0 0)
+            , testCase "LocalTime rollover" $
+                assertEqual
+                    "Jan 31 + 1 month rolls over to Mar 3"
+                    (localTime 2001 3 3 0 0 0)
+                    (addLocalDurationRollOver (CalendarDiffTime 1 0) $ localTime 2001 1 31 0 0 0)
+            , testCase "time part" $
+                assertEqual
+                    "the time part can carry into the next day"
+                    (localTime 2001 2 1 0 0 1)
+                    (addLocalDurationClip (CalendarDiffTime 0 2) $ localTime 2001 1 31 23 59 59)
+            ]
+        , testGroup
+            "diff"
+            [ testCase "UTC clip" $
+                assertEqual
+                    "Mar 1 - Jan 30 clips as 1 month and 1 day"
+                    (CalendarDiffTime 1 nominalDay)
+                    (diffUTCDurationClip (utcTime 2001 3 1 0) $ utcTime 2001 1 30 0)
+            , testCase "UTC rollover" $
+                assertEqual
+                    "Mar 1 - Jan 30 rolls over as 30 days"
+                    (CalendarDiffTime 0 $ 30 * nominalDay)
+                    (diffUTCDurationRollOver (utcTime 2001 3 1 0) $ utcTime 2001 1 30 0)
+            , testCase "LocalTime clip" $
+                assertEqual
+                    "Mar 1 - Jan 30 clips as 1 month and 1 day"
+                    (CalendarDiffTime 1 nominalDay)
+                    (diffLocalDurationClip (localTime 2001 3 1 0 0 0) $ localTime 2001 1 30 0 0 0)
+            , testCase "LocalTime rollover" $
+                assertEqual
+                    "Mar 1 - Jan 30 rolls over as 30 days"
+                    (CalendarDiffTime 0 $ 30 * nominalDay)
+                    (diffLocalDurationRollOver (localTime 2001 3 1 0 0 0) $ localTime 2001 1 30 0 0 0)
+            ]
+        ]
+
 testReadShowExact :: (Read a, Show a, Eq a) => String -> a -> TestTree
 testReadShowExact t v =
     nameTest
@@ -31,4 +116,6 @@
         , testReadShowExact "P-1Y-1M-1DT1S" $ CalendarDiffTime (-13) $ secondsToNominalDiffTime $ negate 86399
         , testReadShowExact "P-1Y-1M-1D" $ CalendarDiffTime (-13) $ secondsToNominalDiffTime $ negate 86400
         , testReadShowExact "P-1Y-1M-2DT23H59M59S" $ CalendarDiffTime (-13) $ secondsToNominalDiffTime $ negate 86401
+        , testAddDiffs
+        , testSpecifics
         ]
diff --git a/test/template/Main.hs b/test/template/Main.hs
--- a/test/template/Main.hs
+++ b/test/template/Main.hs
@@ -1,9 +1,16 @@
+{-# LANGUAGE CPP #-}
+
 module Main (main) where
 
 import Data.Time.Clock
-import Language.Haskell.TH.Syntax qualified as TH
+#if __GLASGOW_HASKELL__ >= 914
+import qualified Language.Haskell.TH.Lift as TH
+#else
+import qualified Language.Haskell.TH.Syntax as TH
+#endif
 import Test.Tasty
 import Test.Tasty.HUnit
+import Test.TastyWrapper
 
 testLift :: TestTree
 testLift =
@@ -21,4 +28,4 @@
         ]
 
 main :: IO ()
-main = defaultMain tests
+main = tastyWrapper $ defaultMain tests
diff --git a/test/template/Test/TastyWrapper.hs b/test/template/Test/TastyWrapper.hs
new file mode 100644
--- /dev/null
+++ b/test/template/Test/TastyWrapper.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE CPP #-}
+
+module Test.TastyWrapper where
+
+#if defined(javascript_HOST_ARCH)
+import GHC.IO.Handle (hDuplicateTo)
+import System.IO (IOMode (ReadMode), stdin, withFile)
+#endif
+
+tastyWrapper :: IO a -> IO a
+#if defined(javascript_HOST_ARCH)
+-- Tasty's console reporter queries terminal width through ansi-terminal, which
+-- trips h$fdReady in the JS RTS when this test runs attached to a TTY.
+tastyWrapper action =
+    withFile "/dev/null" ReadMode $ \devNull -> do
+        hDuplicateTo devNull stdin
+        action
+#else
+tastyWrapper = id
+#endif
diff --git a/time.cabal b/time.cabal
--- a/time.cabal
+++ b/time.cabal
@@ -1,6 +1,6 @@
 cabal-version:  3.0
 name:           time
-version:        1.15
+version:        1.16
 stability:      stable
 license:        BSD-2-Clause
 license-file:   LICENSE
@@ -14,8 +14,9 @@
 build-type:     Configure
 tested-with:
     GHC == 9.8.4,
-    GHC == 9.10.2,
-    GHC == 9.12.2
+    GHC == 9.10.3,
+    GHC == 9.12.4,
+    GHC == 9.14.1
 x-follows-version-policy:
 
 extra-source-files:
@@ -54,8 +55,13 @@
     build-depends:
         base >= 4.19 && < 5,
         deepseq >= 1.1,
-    if impl(ghc)
-        build-depends: template-haskell >= 2.17,
+    -- template-haskell-lift was added as a boot library in GHC-9.14
+    -- once we no longer wish to backport releases to older major releases,
+    -- this conditional can be dropped
+    if impl(ghc < 9.14)
+        build-depends: template-haskell
+    elif impl(ghc)
+        build-depends: template-haskell-lift >= 0.1 && <0.2
     if os(windows)
         build-depends: Win32
     exposed-modules:
@@ -175,9 +181,13 @@
         tasty,
         tasty-hunit,
         tasty-quickcheck,
-        template-haskell
+    if impl(ghc < 9.14)
+        build-depends: template-haskell
+    elif impl(ghc)
+        build-depends: template-haskell-lift >= 0.1 && <0.2
     main-is: Main.hs
     other-modules:
+        Test.AddDiff
         Test.Types
         Test.TestUtil
         Test.Arbitrary
@@ -235,8 +245,13 @@
         tasty,
         tasty-hunit,
         tasty-quickcheck,
-        template-haskell
+    if impl(ghc < 9.14)
+        build-depends: template-haskell
+    elif impl(ghc)
+        build-depends: template-haskell-lift >= 0.1 && <0.2
     main-is: Main.hs
+    other-modules:
+        Test.TastyWrapper
 
 test-suite test-unix
     if os(windows) || arch (javascript) || arch (wasm32)
@@ -275,4 +290,8 @@
         deepseq,
         time,
         criterion
+    if impl(ghc < 9.14)
+        build-depends: template-haskell
+    elif impl(ghc)
+        build-depends: template-haskell-lift >= 0.1 && <0.2
     main-is: Main.hs