diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,8 +9,15 @@
 o'clock uses [PVP Versioning][1].
 The change log is available [on GitHub][2].
 
-Unreleased
+1.4.0
 =====
+
+* [#136](https://github.com/serokell/o-clock/pull/136)
+  + Remove `toNum`.
+* [#139](https://github.com/serokell/o-clock/pull/139)
+  + Add `Data` instance to `Time`.
+* [#140](https://github.com/serokell/o-clock/pull/140)
+  + Increase some upper bounds.
 
 1.3.0
 =====
diff --git a/o-clock.cabal b/o-clock.cabal
--- a/o-clock.cabal
+++ b/o-clock.cabal
@@ -4,7 +4,7 @@
 -- SPDX-License-Identifier: MPL-2.0
 
 name:                o-clock
-version:             1.3.0
+version:             1.4.0
 synopsis:            Type-safe time library.
 description:         See README.md for details.
 homepage:            https://github.com/serokell/o-clock
@@ -20,11 +20,10 @@
 extra-doc-files:     CHANGELOG.md
                    , README.md
                    , README.lhs
-tested-with:         GHC == 8.6.5
-                   , GHC == 8.8.3
-                   , GHC == 8.10.4
-                   , GHC == 9.0.2
-                   , GHC == 9.2.4
+tested-with:         GHC == 9.0.2
+                   , GHC == 9.2.8
+                   , GHC == 9.4.5
+                   , GHC == 9.6.2
 
 source-repository head
   type:     git
@@ -50,7 +49,7 @@
                        TypeApplications
                        TypeFamilies
   if flag(aeson)
-    build-depends:     aeson    >= 1.2.4 && < 2.1
+    build-depends:     aeson    >= 1.2.4 && < 2.3
                      , text
     cpp-options:       -DHAS_aeson
 
@@ -74,10 +73,10 @@
                        Test.Time.Units
 
   build-depends:       o-clock
-                     , hedgehog       >= 0.6 && < 1.3
+                     , hedgehog       >= 0.6 && < 1.4
                      , hspec-expectations ^>= 0.8
-                     , tasty          >= 0.12 && < 1.5
-                     , tasty-hedgehog >= 0.1 && < 1.3.2
+                     , tasty          >= 0.12 && < 1.6
+                     , tasty-hedgehog >= 0.1 && < 1.5.0
                      , tasty-hunit-compat ^>= 0.2
                      , type-spec      >= 0.3.0.1 && < 0.5
 
@@ -95,7 +94,7 @@
   main-is:             Doctest.hs
 
   build-tool-depends:  doctest:doctest
-  build-depends:       doctest >= 0.16 && < 0.21
+  build-depends:       doctest >= 0.16 && < 0.23
                      , Glob    >= 0.9 && < 0.11
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N
 
@@ -109,7 +108,7 @@
 
   build-tool-depends:  markdown-unlit:markdown-unlit
   build-depends:       o-clock
-                     , markdown-unlit ^>= 0.5
+                     , markdown-unlit >= 0.5 && < 0.7
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N -pgmL markdown-unlit
 
 benchmark o-clock-benchmark
diff --git a/src/Time/Rational.hs b/src/Time/Rational.hs
--- a/src/Time/Rational.hs
+++ b/src/Time/Rational.hs
@@ -1,18 +1,28 @@
--- SPDX-FileCopyrightText: 2019 Serokell <https://serokell.io>
+-- SPDX-FileCopyrightText: 2019-2023 Serokell <https://serokell.io>
 --
 -- SPDX-License-Identifier: MPL-2.0
 
 {-# LANGUAGE AllowAmbiguousTypes  #-}
 {-# LANGUAGE CPP                  #-}
 {-# LANGUAGE ConstraintKinds      #-}
+{-# LANGUAGE DataKinds            #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE NoStarIsType         #-}
+{-# LANGUAGE PolyKinds            #-}
 {-# LANGUAGE Rank2Types           #-}
-{-# LANGUAGE TypeInType           #-}
 {-# LANGUAGE TypeOperators        #-}
 {-# LANGUAGE UndecidableInstances #-}
 
+-- See https://github.com/ghc/ghc/commit/13d627bbd0bc3dd30d672de341aa7f471be0aa2c
+-- Starting from 9.6, GHC doesn't print promotion ticks when they are not necessary.
+-- Because of that we need to support too many cases in doctests.
+-- Let's force redundant ticks for now and remove this flag later when we stop
+-- supporting 9.0 at least.
+#if ( __GLASGOW_HASKELL__ >= 906 )
+{-# OPTIONS_GHC -fprint-redundant-promotion-ticks #-}
+#endif
+
 -- | This module introduces 'Rat' kind and all necessary functional.
 
 module Time.Rational
@@ -43,6 +53,11 @@
 import GHC.TypeNats (Div, KnownNat, Mod, Nat, natVal, type (<=?))
 import qualified GHC.TypeNats
 import Unsafe.Coerce (unsafeCoerce)
+
+#if ( __GLASGOW_HASKELL__ >= 906 )
+-- $setup
+-- >>> {-# OPTIONS_GHC -fprint-redundant-promotion-ticks #-}
+#endif
 
 -- | Data structure represents the rational number.
 -- Rational number can be represented as a pair of
diff --git a/src/Time/Units.hs b/src/Time/Units.hs
--- a/src/Time/Units.hs
+++ b/src/Time/Units.hs
@@ -6,6 +6,7 @@
 {-# LANGUAGE CPP                        #-}
 {-# LANGUAGE ConstraintKinds            #-}
 {-# LANGUAGE DataKinds                  #-}
+{-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE DeriveGeneric              #-}
 {-# LANGUAGE ExplicitForAll             #-}
 {-# LANGUAGE FlexibleContexts           #-}
@@ -45,7 +46,6 @@
        , floorRat
        , ceilingUnit
        , ceilingRat
-       , toNum
        , toFractional
 
        , sec
@@ -71,6 +71,7 @@
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Data.Char (isDigit, isLetter)
 import Data.Coerce (coerce)
+import Data.Data (Data)
 import Data.Foldable (foldl')
 import Data.Proxy (Proxy (..))
 import Data.Semigroup (Semigroup (..))
@@ -116,7 +117,7 @@
 
 -- | Time unit is represented as type level rational multiplier with kind 'Rat'.
 newtype Time (rat :: Rat) = Time { unTime :: RatioNat }
-    deriving (Eq, Ord, Enum, Generic)
+    deriving (Eq, Ord, Enum, Generic, Data)
 
 -- | Addition is associative binary operation for 'Semigroup' of 'Time'.
 instance Semigroup (Time (rat :: Rat)) where
@@ -342,41 +343,6 @@
 -}
 ceilingUnit :: forall (unit :: Rat) . Time unit -> Time unit
 ceilingUnit = time . fromIntegral @Natural . ceilingRat
-
-{- | Convert time to the 'Num' in given units.
-
-For example, instead of writing
-
-@
-foo :: POSIXTime
-foo = 10800  -- 3 hours
-@
-
-one can write more safe implementation:
-
-@
-foo = toNum @Second $ hour 3
-@
-
-__Examples:__
-
->>> toNum @Second @Natural $ hour 3
-10800
-
->>> toNum @Minute @Int $ hour 3
-180
-
->>> toNum @Hour @Natural $ hour 3
-3
-
--}
-toNum :: forall (unitTo :: Rat) n (unit :: Rat) . (KnownDivRat unit unitTo, Num n)
-      => Time unit -> n
-toNum = fromIntegral @Natural . floorRat . toUnit @unitTo
-{-# DEPRECATED toNum
-  [ "May lead to unexpected flooring of the fractional time."
-  , "Use 'toFractional' to avoid rounding or 'floorRat' to keep the flooring behaviour."
-  ] #-}
 
 {- | Convert the 'Time' object to the 'Fractional' value.