diff --git a/libraries/stdlib/samples/test/samples/time/durations.kt b/libraries/stdlib/samples/test/samples/time/durations.kt
index 351395e293f..b8fba255729 100644
--- a/libraries/stdlib/samples/test/samples/time/durations.kt
+++ b/libraries/stdlib/samples/test/samples/time/durations.kt
@@ -30,7 +30,7 @@ class Durations {
         assertPrints(Duration.minutes(1230), "20h 30m")
         assertPrints(Duration.minutes(920), "15h 20m")
         assertPrints(Duration.seconds(1.546), "1.546s")
-        assertPrints(Duration.milliseconds(25.12), "0.025120s")
+        assertPrints(Duration.milliseconds(25.12), "25.120ms")
     }
 
     @Sample
diff --git a/libraries/stdlib/src/kotlin/time/Duration.kt b/libraries/stdlib/src/kotlin/time/Duration.kt
index 69697c20fe9..687a23268a3 100644
--- a/libraries/stdlib/src/kotlin/time/Duration.kt
+++ b/libraries/stdlib/src/kotlin/time/Duration.kt
@@ -692,19 +692,16 @@ public value class Duration internal constructor(private val rawValue: Long) : C
                         }
                         if (hasSeconds) {
                             if (length > 1) append(' ')
-                            append(seconds)
-                            if (nanoseconds != 0) {
-                                append('.')
-                                when {
-                                    (nanoseconds % 1_000_000 == 0) ->
-                                        append((nanoseconds / 1_000_000).toString().padStart(3, '0'))
-                                    (nanoseconds % 1_000 == 0) ->
-                                        append((nanoseconds / 1_000).toString().padStart(6, '0'))
-                                    else ->
-                                        append(nanoseconds.toString().padStart(9, '0'))
-                                }
+                            when {
+                                seconds != 0 || hasDays || hasHours || hasMinutes ->
+                                    appendFractional(seconds, nanoseconds, "s")
+                                nanoseconds >= 1_000_000 ->
+                                    appendFractional(nanoseconds / 1_000_000, nanoseconds % 1_000_000 * 1_000, "ms")
+                                nanoseconds >= 1_000 ->
+                                    appendFractional(nanoseconds / 1_000, nanoseconds % 1_000 * 1_000_000, "us")
+                                else ->
+                                    append(nanoseconds).append("ns")
                             }
-                            append('s')
                         }
                     }
                 }
@@ -712,11 +709,18 @@ public value class Duration internal constructor(private val rawValue: Long) : C
         }
     }
 
-    private fun precision(value: Double): Int = when {
-        value < 1 -> 3
-        value < 10 -> 2
-        value < 100 -> 1
-        else -> 0
+    private fun StringBuilder.appendFractional(whole: Int, nanoFractional: Int, unit: String) {
+        append(whole)
+        if (nanoFractional != 0) {
+            append('.')
+            val nanoString = nanoFractional.toString().padStart(9, '0')
+            when {
+                nanoFractional % 1_000_000 == 0 -> appendRange(nanoString, 0, 3)
+                nanoFractional % 1_000 == 0 -> appendRange(nanoString, 0, 6)
+                else -> append(nanoString)
+            }
+        }
+        append(unit)
     }
 
     /**
@@ -771,17 +775,7 @@ public value class Duration internal constructor(private val rawValue: Long) : C
                 append(minutes).append('M')
             }
             if (hasSeconds || (!hasHours && !hasMinutes)) {
-                append(seconds)
-                if (nanoseconds != 0) {
-                    append('.')
-                    val nss = nanoseconds.toString().padStart(9, '0')
-                    when {
-                        nanoseconds % 1_000_000 == 0 -> appendRange(nss, 0, 3)
-                        nanoseconds % 1_000 == 0 -> appendRange(nss, 0, 6)
-                        else -> append(nss)
-                    }
-                }
-                append('S')
+                appendFractional(seconds, nanoseconds, "S")
             }
         }
     }
diff --git a/libraries/stdlib/test/time/DurationTest.kt b/libraries/stdlib/test/time/DurationTest.kt
index 2a070ab5183..de7f422bc69 100644
--- a/libraries/stdlib/test/time/DurationTest.kt
+++ b/libraries/stdlib/test/time/DurationTest.kt
@@ -568,26 +568,26 @@ class DurationTest {
         test(Duration.seconds(1.3), "1.300s")
         test(Duration.seconds(1), "1s")
 
-        test(Duration.seconds(0.5), "0.500s")
-        test(Duration.milliseconds(40.2), "0.040200s")
-        test(Duration.milliseconds(4.225), "0.004225s")
-        test(Duration.milliseconds(4.245), "0.004245s")
-        test(Duration.milliseconds(1), "0.001s")
+        test(Duration.seconds(0.5), "500ms")
+        test(Duration.milliseconds(40.2), "40.200ms")
+        test(Duration.milliseconds(4.225), "4.225ms")
+        test(Duration.milliseconds(4.24501), "4.245010ms")
+        test(Duration.milliseconds(1), "1ms")
 
-        test(Duration.milliseconds(0.75), "0.000750s")
-        test(Duration.microseconds(75.35), "0.000075350s")
-        test(Duration.microseconds(7.25), "0.000007250s")
-        test(Duration.microseconds(1.035), "0.000001035s")
-        test(Duration.microseconds(1.005), "0.000001005s")
+        test(Duration.milliseconds(0.75), "750us")
+        test(Duration.microseconds(75.35), "75.350us")
+        test(Duration.microseconds(7.25), "7.250us")
+        test(Duration.microseconds(1.035), "1.035us")
+        test(Duration.microseconds(1.005), "1.005us")
 
-        test(Duration.nanoseconds(950.5), "0.000000951s")
-        test(Duration.nanoseconds(85.23), "0.000000085s")
-        test(Duration.nanoseconds(8.235), "0.000000008s")
-        test(Duration.nanoseconds(1.3), "0.000000001s")
+        test(Duration.nanoseconds(950.5), "951ns")
+        test(Duration.nanoseconds(85.23), "85ns")
+        test(Duration.nanoseconds(8.235), "8ns")
+        test(Duration.nanoseconds(1.3), "1ns")
+        test(Duration.nanoseconds(0.75), "1ns")
+        test(Duration.nanoseconds(0.7512), "1ns")
 
         // equal to zero
-//        test(Duration.nanoseconds(0.75), "0.75ns")
-//        test(Duration.nanoseconds(0.7512), "0.7512ns")
 //        test(Duration.nanoseconds(0.023), "0.023ns")
 //        test(Duration.nanoseconds(0.0034), "0.0034ns")
 //        test(Duration.nanoseconds(0.0000035), "0.0000035ns")