diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Revision history for time-domain
 
+## 1.7
+
+* Introduce `Seconds` time domain
+* Base the `TimeDomain` class hierarchy on `Group` (from `monoid-extras`) and `RightAction` (from `changeset`)
+* Extend the `TimeDifference` type class
+
 ## 0.1.0.5
 
 * Support GHC 9.10
diff --git a/src/Data/TimeDomain.hs b/src/Data/TimeDomain.hs
--- a/src/Data/TimeDomain.hs
+++ b/src/Data/TimeDomain.hs
@@ -1,7 +1,12 @@
+{-# LANGUAGE DeriveTraversable #-}
+{-# LANGUAGE DerivingVia #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE UndecidableInstances #-}
 
 {- |
 This module defines the 'TimeDomain' class.
@@ -15,9 +20,18 @@
 )
 where
 
+-- base
+import Data.Monoid (Sum (..))
+
 -- time
 import Data.Time.Clock (UTCTime, addUTCTime, diffUTCTime)
 
+-- groups
+import Data.Group (Group (..))
+
+-- changeset
+import Data.Monoid.RightAction (RightAction (actRight), RightTorsor (differenceRight))
+
 {- |
 A time domain is an affine space representing a notion of time,
 such as real time, simulated time, steps, or a completely different notion.
@@ -28,86 +42,93 @@
 * @(t `addTime` dt) `diffTime` t = dt@
 * @(t `addTime` dt1) `addTime` dt2 = t `addTime` (dt1 `add` dt2)@
 -}
-class (TimeDifference (Diff time)) => TimeDomain time where
+class (RightAction (Diff time) time, RightTorsor (Diff time) time, TimeDifference (Diff time)) => TimeDomain time where
   -- | The type of differences or durations between two timestamps
   type Diff time
 
-  -- | Compute the difference between two timestamps.
-  --
-  --   Mnemonic: 'diffTime' behaves like the '(-)' operator:
-  --
-  --   @'diffTime' earlier later = later `'diffTime'` earlier@ is the duration it takes from @earlier@ to @later@.
+  {- | Compute the difference between two timestamps.
+
+  Mnemonic: 'diffTime' behaves like the '(-)' operator:
+
+  @'diffTime' earlier later = later `'diffTime'` earlier@ is the duration it takes from @earlier@ to @later@.
+  -}
   diffTime :: time -> time -> Diff time
+  diffTime = differenceRight
 
   -- | Add a time difference to a timestamp.
   addTime :: time -> Diff time -> time
+  addTime = actRight
 
 {- | A type of durations, or differences betweens time stamps.
 
 Expected laws:
 
+* @dt `add` 'zero' = dt@ and @dt `difference` 'zero' = dt@
 * `add` is commutative and associative
 * @(dt1 `difference` dt2) `add` dt2 = dt1@
 -}
-class TimeDifference d where
-  -- | Calculate the difference between two durations,
-  --   compatibly with 'diffTime'.
+class (Group d) => TimeDifference d where
+  {- | The zero duration, i.e. no time has passed.
+  Additive identity for 'difference' and 'add'.
+  -}
+  zero :: d
+  zero = mempty
+
+  {- | Calculate the difference between two durations,
+  compatibly with 'diffTime'.
+  -}
   difference :: d -> d -> d
+  difference = (~~)
 
   -- | Add two time differences.
   add :: d -> d -> d
+  add = (<>)
 
--- | Differences between 'UTCTime's are measured in seconds.
+-- | Differences between 'UTCTime's are measured in Secondss.
 instance TimeDomain UTCTime where
-  type Diff UTCTime = Double
-  diffTime t1 t2 = realToFrac $ diffUTCTime t1 t2
-  addTime = flip $ addUTCTime . realToFrac
-
-instance TimeDifference Double where
-  difference = (-)
-  add = (+)
-
-instance TimeDomain Double where
-  type Diff Double = Double
-  diffTime = (-)
-  addTime = (+)
-
-instance TimeDifference Float where
-  difference = (-)
-  add = (+)
-
-instance TimeDomain Float where
-  type Diff Float = Float
-  diffTime = (-)
-  addTime = (+)
+  type Diff UTCTime = Seconds Double
 
-instance TimeDifference Integer where
-  difference = (-)
-  add = (+)
+instance RightAction (Seconds Double) UTCTime where
+  actRight = flip $ addUTCTime . realToFrac . getSeconds
 
-instance TimeDomain Integer where
-  type Diff Integer = Integer
-  diffTime = (-)
-  addTime = (+)
+instance RightTorsor (Seconds Double) UTCTime where
+  differenceRight t1 t2 = Seconds $ realToFrac $ diffUTCTime t1 t2
 
 instance TimeDifference () where
+  zero = ()
   difference _ _ = ()
   add _ _ = ()
 
 instance TimeDomain () where
   type Diff () = ()
-  diffTime _ _ = ()
-  addTime _ _ = ()
 
--- | Any 'Num' can be wrapped to form a 'TimeDomain'.
-newtype NumTimeDomain a = NumTimeDomain {fromNumTimeDomain :: a}
-  deriving (Num)
+{- | Any 'Num' can be wrapped to form a 'TimeDomain'.
 
-instance (Num a) => TimeDifference (NumTimeDomain a) where
-  difference = (-)
-  add = (+)
+The number 1 is interpreted as one second.
+-}
+newtype Seconds a = Seconds {getSeconds :: a}
+  deriving newtype (Show, Read, Eq, Ord, Num, Fractional, Floating, Real, RealFrac, RealFloat, Enum, Bounded, Integral)
+  deriving stock (Functor, Foldable, Traversable)
 
-instance (Num a) => TimeDomain (NumTimeDomain a) where
-  type Diff (NumTimeDomain a) = NumTimeDomain a
-  diffTime = (-)
-  addTime = (+)
+deriving via Sum (Seconds a) instance (Num a) => Semigroup (Seconds a)
+deriving via Sum (Seconds a) instance (Num a) => Monoid (Seconds a)
+deriving via Sum (Seconds a) instance (Num a) => Group (Seconds a)
+instance (Num a) => TimeDifference (Seconds a)
+
+-- I would have thought I shouldn't be needing this, but it seems to overlap with the Zip instance for some reason.
+instance {-# OVERLAPPING #-} (Num a) => RightAction (Seconds a) (Seconds a) where
+  actRight = (+)
+
+instance (Num a) => RightTorsor (Seconds a) (Seconds a) where
+  differenceRight = (-)
+
+instance (Num a) => TimeDomain (Seconds a) where
+  type Diff (Seconds a) = Seconds a
+
+-- | Scale time differences by a factor.
+instance (Num a) => RightAction a (Seconds a) where
+  actRight seconds factor = fmap (* factor) seconds
+
+-- | Compute the quotient of two time differences.
+instance (Fractional a) => RightTorsor a (Seconds a) where
+  differenceRight (Seconds secondsOrig) (Seconds secondsScaled) = secondsOrig / secondsScaled
diff --git a/time-domain.cabal b/time-domain.cabal
--- a/time-domain.cabal
+++ b/time-domain.cabal
@@ -1,6 +1,6 @@
 cabal-version: 2.4
 name: time-domain
-version: 1.6
+version: 1.7
 license: MIT
 license-file: LICENSE
 author: Manuel Bärenz
@@ -32,6 +32,8 @@
   exposed-modules: Data.TimeDomain
   build-depends:
     base >=4.13.0 && <4.22,
+    changeset ^>=0.2.1,
+    groups ^>=0.5.3,
     time >=1.11 && <1.16,
 
   hs-source-dirs: src