diff --git a/buildSrc/src/test/java/org/springframework/gradle/github/milestones/GitHubMilestoneApiTests.java b/buildSrc/src/test/java/org/springframework/gradle/github/milestones/GitHubMilestoneApiTests.java
index c74b148d71..c49729205b 100644
--- a/buildSrc/src/test/java/org/springframework/gradle/github/milestones/GitHubMilestoneApiTests.java
+++ b/buildSrc/src/test/java/org/springframework/gradle/github/milestones/GitHubMilestoneApiTests.java
@@ -4,6 +4,7 @@ import java.nio.charset.Charset;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalTime;
+import java.time.ZoneId;
 import java.util.concurrent.TimeUnit;
 
 import okhttp3.mockwebserver.MockResponse;
@@ -636,7 +637,7 @@ public class GitHubMilestoneApiTests {
 				"      \"state\":\"open\",\n" +
 				"      \"created_at\":\"2020-09-16T13:28:03Z\",\n" +
 				"      \"updated_at\":\"2021-04-06T23:47:10Z\",\n" +
-				"      \"due_on\":\"" + Instant.now().toString() + "\",\n" +
+				"      \"due_on\":\"" + LocalDate.now().atStartOfDay(ZoneId.systemDefault()).toInstant().toString() + "\",\n" +
 				"      \"closed_at\":null\n" +
 				"   }\n" +
 				"]";