diff --git a/library/TextBuilderDev.hs b/library/TextBuilderDev.hs
--- a/library/TextBuilderDev.hs
+++ b/library/TextBuilderDev.hs
@@ -73,6 +73,8 @@
     utcTimeInIso8601,
     utcTimestampInIso8601,
     intervalInSeconds,
+    diffTimeCompact,
+    picosecondsCompact,
 
     -- * Classes
     IsomorphicToTextBuilder (..),
@@ -595,6 +597,11 @@
 
 -- |
 -- Time interval in seconds.
+--
+-- The format is the following:
+--
+-- > DD:HH:MM:SS
+--
 -- Directly applicable to 'DiffTime' and 'NominalDiffTime'.
 {-# INLINEABLE intervalInSeconds #-}
 intervalInSeconds :: (RealFrac seconds) => seconds -> TextBuilder
@@ -611,6 +618,31 @@
     <> padFromLeft 2 '0' (decimal minutes)
     <> ":"
     <> padFromLeft 2 '0' (decimal seconds)
+
+-- | DiffTime in a compact decimal format based on 'picosecondsCompact'.
+diffTimeCompact :: DiffTime -> TextBuilder
+diffTimeCompact = picosecondsCompact . diffTimeToPicoseconds
+
+-- | Amount of picoseconds represented in a compact decimal format using suffixes.
+--
+-- E.g., the following is @1_230_000_000@ picoseconds or 1.23 milliseconds or 1230 microseconds:
+--
+-- > 1230us
+picosecondsCompact :: Integer -> TextBuilder
+picosecondsCompact x =
+  attemptOr 1_000_000_000_000 "s"
+    $ attemptOr 1_000_000_000 "ms"
+    $ attemptOr 1_000_000 "us"
+    $ attemptOr 1_000 "ns"
+    $ decimal x
+    <> "ps"
+  where
+    attemptOr factor suffix alternative =
+      if x == divided * factor
+        then decimal divided <> suffix
+        else alternative
+      where
+        divided = div x factor
 
 -- | Double with a fixed number of decimal places.
 {-# INLINE fixedDouble #-}
diff --git a/text-builder-dev.cabal b/text-builder-dev.cabal
--- a/text-builder-dev.cabal
+++ b/text-builder-dev.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name:          text-builder-dev
-version:       0.3.5
+version:       0.3.6
 category:      Text, Builders
 synopsis:      Edge of developments for "text-builder"
 description:
@@ -47,6 +47,7 @@
     MagicHash
     MultiParamTypeClasses
     MultiWayIf
+    NumericUnderscores
     OverloadedStrings
     ParallelListComp
     PatternGuards