@@ -38,6 +38,7 @@
 ### Fixes
 
 - Keep resolving the server name after `Sentry.close()` or a re-init. Closing the SDK shut down the shared hostname cache for the life of the process, so `server_name` silently froze at the value it had last resolved ([#6119](https://github.com/getsentry/sentry-java/pull/6119))
+- Order breadcrumbs by the timestamp they carry rather than by when they were created in the current process, so breadcrumbs restored from disk or handed over by a hybrid SDK no longer sort as if they had just happened ([#6097](https://github.com/getsentry/sentry-java/pull/6097))
 
 ### Internal
 
 
@@ -73,7 +73,9 @@ public Breadcrumb(final long timestamp) {
   }
 
   Breadcrumb(final @NotNull Breadcrumb breadcrumb) {
-    this.nanos = System.nanoTime();
+    // A clone stands in for the breadcrumb it was copied from, so it inherits its tie-breaker
+    // instead of taking a fresh one and sorting after everything recorded since.
+    this.nanos = breadcrumb.nanos;
     this.timestamp = breadcrumb.timestamp;
     this.timestampMs = breadcrumb.timestampMs;
     this.message = breadcrumb.message;
@@ -832,6 +834,12 @@ public void setUnknown(@Nullable Map<String, Object> unknown) {
   @Override
   @SuppressWarnings("JavaUtilDate")
   public int compareTo(@NotNull Breadcrumb o) {
+    final int byTimestamp = getTimestamp().compareTo(o.getTimestamp());
+    if (byTimestamp != 0) {
+      return byTimestamp;
+    }
+    // Timestamps are millisecond-granular, so breadcrumbs recorded in the same millisecond tie.
+    // nanos is only meaningful within a process run, which is all a tie-breaker has to cover.
     return nanos.compareTo(o.nanos);
   }
 
 
@@ -26,7 +26,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import org.jetbrains.annotations.ApiStatus;
@@ -41,7 +40,6 @@ public final class SentryClient implements ISentryClient {
 
   private final @NotNull SentryOptions options;
   private final @NotNull ITransport transport;
-  private final @NotNull SortBreadcrumbsByDate sortBreadcrumbsByDate = new SortBreadcrumbsByDate();
   private final @NotNull ILoggerBatchProcessor loggerBatchProcessor;
   private final @NotNull IMetricsBatchProcessor metricsBatchProcessor;
 
@@ -1660,7 +1658,7 @@ private void sortBreadcrumbsByDate(
 
     if (sortedBreadcrumbs != null && !breadcrumbs.isEmpty()) {
       sortedBreadcrumbs.addAll(breadcrumbs);
-      Collections.sort(sortedBreadcrumbs, sortBreadcrumbsByDate);
+      Collections.sort(sortedBreadcrumbs);
     }
   }
 
@@ -1851,13 +1849,4 @@ private boolean sample() {
     }
     return true;
   }
-
-  private static final class SortBreadcrumbsByDate implements Comparator<Breadcrumb> {
-
-    @SuppressWarnings({"JdkObsolete", "JavaUtilDate"})
-    @Override
-    public int compare(final @NotNull Breadcrumb b1, final @NotNull Breadcrumb b2) {
-      return b1.getTimestamp().compareTo(b2.getTimestamp());
-    }
-  }
 }
@@ -1,5 +1,7 @@
 package io.sentry
 
+import com.google.common.truth.Truth.assertThat
+import java.io.StringReader
 import java.util.Date
 import java.util.concurrent.CountDownLatch
 import java.util.concurrent.Executors
@@ -365,6 +367,60 @@ class BreadcrumbTest {
     }
   }
 
+  @Test
+  fun `breadcrumbs sharing a timestamp keep the order they were recorded in`() {
+    val timestamp = Date(1_600_000_000_000)
+    val first = Breadcrumb(timestamp).apply { message = "first" }
+    val second = Breadcrumb(timestamp).apply { message = "second" }
+    val third = Breadcrumb(timestamp).apply { message = "third" }
+
+    val sorted = listOf(third, first, second).sorted().map { it.message }
+
+    assertThat(sorted).containsExactly("first", "second", "third").inOrder()
+  }
+
+  @Test
+  fun `a deserialized breadcrumb is ordered by its own timestamp, not by when it was parsed`() {
+    val live = Breadcrumb(Date(1_600_000_000_000)).apply { message = "live" }
+    val restored =
+      Breadcrumb.fromMap(
+        mapOf(
+          Breadcrumb.JsonKeys.TIMESTAMP to DateUtils.getTimestamp(Date(1_500_000_000_000)),
+          Breadcrumb.JsonKeys.MESSAGE to "restored",
+        ),
+        SentryOptions(),
+      )
+
+    val sorted = listOf(live, restored).sorted().map { it.message }
+
+    assertThat(sorted).containsExactly("restored", "live").inOrder()
+  }
+
+  @Test
+  fun `a breadcrumb read back from JSON is ordered by its own timestamp, not by when it was parsed`() {
+    val live = Breadcrumb(Date(1_600_000_000_000)).apply { message = "live" }
+    val json =
+      """{"timestamp":"${DateUtils.getTimestamp(Date(1_500_000_000_000))}","message":"restored"}"""
+    val restored =
+      Breadcrumb.Deserializer()
+        .deserialize(JsonObjectReader(StringReader(json)), NoOpLogger.getInstance())
+
+    val sorted = listOf(live, restored).sorted().map { it.message }
+
+    assertThat(sorted).containsExactly("restored", "live").inOrder()
+  }
+
+  @Test
+  fun `cloning a breadcrumb keeps its position among breadcrumbs sharing its timestamp`() {
+    val timestamp = Date(1_600_000_000_000)
+    val first = Breadcrumb(timestamp).apply { message = "first" }
+    val second = Breadcrumb(timestamp).apply { message = "second" }
+
+    val sorted = listOf(second, Breadcrumb(first)).sorted().map { it.message }
+
+    assertThat(sorted).containsExactly("first", "second").inOrder()
+  }
+
   class TestKey(val id: Long) {
     override fun toString(): String = id.toString()
   }