Fix unit test

Author: courtneyeh

Diff for: ethereum/statetransition/src/test/java/tech/pegasys/teku/statetransition/util/DebugDataDumperTest.java

@@ -22,6 +22,9 @@
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
+import java.sql.Date;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
 import java.util.Optional;
 import org.apache.tuweni.bytes.Bytes;
 import org.junit.jupiter.api.Test;
@@ -162,14 +165,20 @@ void formatTimestamp_shouldFormatDate() {
     final DebugDataDumper manager = new DebugDataDumper(Path.of("."), true);
     final String formattedTimestamp =
         manager.formatOptionalTimestamp(Optional.of(timeProvider.getTimeInMillis()));
-    assertThat(formattedTimestamp).isEqualTo("1970-01-01T12_46_40.00");
+
+    final DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH_mm_ss.SS");
+    final Date date = new Date(timeProvider.getTimeInMillis().longValue());
+    assertThat(formattedTimestamp).isEqualTo(df.format(date));
   }
 
   @Test
   void generateTimestamp_shouldGenerateTimestamp() {
     final DebugDataDumper manager = new DebugDataDumper(Path.of("."), true);
     final String formattedTimestamp = manager.generateTimestamp(timeProvider);
-    assertThat(formattedTimestamp).isEqualTo("1970-01-01T12_46_40.00");
+
+    final DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH_mm_ss.SS");
+    final Date date = new Date(timeProvider.getTimeInMillis().longValue());
+    assertThat(formattedTimestamp).isEqualTo(df.format(date));
   }
 
   private void checkBytesSavedToFile(final Path path, final Bytes expectedBytes) {