diff --git a/src/main/java/com/google/devtools/build/lib/profiler/JsonTraceFileWriter.java b/src/main/java/com/google/devtools/build/lib/profiler/JsonTraceFileWriter.java
index ae3cd9e8c3d73f..d73fa42380960f 100644
--- a/src/main/java/com/google/devtools/build/lib/profiler/JsonTraceFileWriter.java
+++ b/src/main/java/com/google/devtools/build/lib/profiler/JsonTraceFileWriter.java
@@ -225,15 +225,15 @@ public void run() {
               // The buffer size of 262144 is chosen at random.
               new OutputStreamWriter(
                   new BufferedOutputStream(outStream, 262144), StandardCharsets.UTF_8))) {
-        var finishDate = Instant.now();
+        var startDate = Instant.now();
         writer.beginObject();
         writer.name("otherData");
         writer.beginObject();
         writer.name("bazel_version").value(BlazeVersionInfo.instance().getReleaseName());
         writer.name("build_id").value(buildID.toString());
         writer.name("output_base").value(outputBase);
-        writer.name("date").value(finishDate.toString());
-        writer.name("profile_finish_ts").value(finishDate.getEpochSecond() * 1000);
+        writer.name("date").value(startDate.toString());
+        writer.name("profile_start_ts").value(startDate.toEpochMilli());
         writer.endObject();
         writer.name("traceEvents");
         writer.beginArray();