diff --git a/chronos.cabal b/chronos.cabal
--- a/chronos.cabal
+++ b/chronos.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: chronos
-version: 1.1.5.1
+version: 1.1.6.0
 synopsis: A high-performance time library
 description:
   Chronos is a performance-oriented time library for Haskell, with a
@@ -35,6 +35,7 @@
 copyright: 2016 Andrew Martin
 category: Data, Time, Parsing, Development
 build-type: Simple
+tested-with: GHC ==8.10.7 || ==9.0.2 || ==9.2.8 || ==9.4.8 || ==9.6.4 || ==9.8.1
 
 library
   hs-source-dirs: src
@@ -46,18 +47,18 @@
     -- it is OPTIONS_HADDOCK-hidden
       Chronos.Internal.CTimespec
   build-depends:
-    , aeson >= 1.1 && < 2.2
+    , aeson >= 1.1 && < 2.3
     , attoparsec >= 0.13 && < 0.15
-    , base >= 4.14 && < 4.19
-    , bytestring >= 0.10 && < 0.12
+    , base >= 4.14 && < 4.20
+    , bytestring >= 0.10 && < 0.13
     , deepseq >= 1.4.4.0
     , hashable >= 1.2 && < 1.5
     , primitive >= 0.6.4 && < 0.10
     , semigroups >= 0.16 && < 0.21
-    , text >= 1.2 && < 1.3 || >= 2.0 && < 2.1
+    , text >= 1.2 && < 1.3 || >= 2.0 && < 2.2
     , torsor >= 0.1 && < 0.2
     , vector >= 0.11 && < 0.14
-    , bytebuild >= 0.3.8 && < 0.4
+    , bytebuild >= 0.3.16 && < 0.4
     , bytesmith >= 0.3.7 && < 0.4
     , byteslice >= 0.2.5.2 && <0.3
     , text-short >= 0.1.3 && <0.2
diff --git a/src/Chronos.hs b/src/Chronos.hs
--- a/src/Chronos.hs
+++ b/src/Chronos.hs
@@ -1,5 +1,6 @@
 {-# language BangPatterns #-}
 {-# language CPP #-}
+{-# language DataKinds #-}
 {-# language DeriveGeneric #-}
 {-# language GeneralizedNewtypeDeriving #-}
 {-# language LambdaCase #-}
@@ -11,7 +12,6 @@
 {-# language ScopedTypeVariables #-}
 {-# language TypeApplications #-}
 {-# language TypeFamilies #-}
-{-# language TypeInType #-}
 {-# language UnboxedTuples #-}
 
 {-| Chronos is a performance-oriented time library for Haskell, with a
@@ -116,6 +116,9 @@
   , daysInMonth
   , isLeapYear
   , observedOffsets
+  , sinceEpoch
+  , asSeconds
+
     -- * Textual Conversion
     -- ** Date
     -- *** Text
@@ -727,6 +730,19 @@
   , 1400
   ]
 
+-- | Compute the 'Timespan' between the given date and 'epoch'.
+--
+-- @since 1.1.6.0
+sinceEpoch :: Time -> Timespan
+sinceEpoch t = difference t epoch
+
+-- | Convert a 'Timespan' to its equivalent in seconds.
+--
+-- @since 1.1.6.0
+asSeconds :: Timespan -> Int64
+asSeconds (Timespan t) = case second of
+  Timespan s -> t `div` s
+
 -- | The first argument in the resulting tuple in a day
 --   adjustment. It should be either -1, 0, or 1, as no
 --   offset should ever exceed 24 hours.
@@ -3516,7 +3532,7 @@
 -- Examples of output:
 --
 -- > 2021-01-05T23:00:51
--- > 2021-01-05T23:00:52.123000000
+-- > 2021-01-05T23:00:52.123
 -- > 2021-01-05T23:00:53.674094347
 boundedBuilderUtf8BytesIso8601Zoneless :: Datetime -> Bounded.Builder 44
 boundedBuilderUtf8BytesIso8601Zoneless (Datetime (Date (Year y) (Month mth) (DayOfMonth d)) (TimeOfDay h mt sns)) =
@@ -3545,10 +3561,16 @@
     `Bounded.append`
     (case ns of
       0 -> Bounded.weaken @0 @10 Lte.constant Bounded.empty
-      _ ->
-        Bounded.ascii '.'
-        `Bounded.append`
-        Bounded.wordPaddedDec9 (fromIntegral ns)
+      _ -> let (ms,us) = quotRem ns 1_000_000 in case us of
+        0 -> Bounded.weaken @4 @10 Lte.constant
+          ( Bounded.ascii '.'
+            `Bounded.append`
+            Bounded.wordPaddedDec3 (fromIntegral ms)
+          )
+        _ ->
+          Bounded.ascii '.'
+          `Bounded.append`
+          Bounded.wordPaddedDec9 (fromIntegral ns)
     )
 
 boundedBuilderOffset :: Offset -> Bounded.Builder 6
diff --git a/src/Chronos/Internal/CTimespec.hs b/src/Chronos/Internal/CTimespec.hs
--- a/src/Chronos/Internal/CTimespec.hs
+++ b/src/Chronos/Internal/CTimespec.hs
@@ -1,5 +1,8 @@
 {-# LANGUAGE CPP #-}
+
+#if defined(ghcjs_HOST_OS)
 {-# LANGUAGE JavaScriptFFI #-}
+#endif
 
 {-# OPTIONS_HADDOCK hide #-} -- for doctests