diff --git a/icu4j/main/classes/core/src/com/ibm/icu/util/SimpleTimeZone.java b/icu4j/main/classes/core/src/com/ibm/icu/util/SimpleTimeZone.java
index 38bec96922..0ed31b890a 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/util/SimpleTimeZone.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/util/SimpleTimeZone.java
@@ -989,7 +989,7 @@ public class SimpleTimeZone extends BasicTimeZone {
             if (startMonth < Calendar.JANUARY || startMonth > Calendar.DECEMBER) {
                 throw new IllegalArgumentException();
             }
-            if (startTime < 0 || startTime >= Grego.MILLIS_PER_DAY ||
+            if (startTime < 0 || startTime > Grego.MILLIS_PER_DAY ||
                 startTimeMode < WALL_TIME || startTimeMode > UTC_TIME) {
                 throw new IllegalArgumentException();
             }