Support configurable start time - emailable report

CHANGES.txt

@@ -1,4 +1,5 @@
 Current
+New  : GITHUB-2459: Support configurable start time - emailable report (Barry Evans)
 Fixed: GITHUB-2467: XmlTest does not copy the xmlClasses during clone (C.V.Aditya)
 Fixed: GITHUB-2469: Parameters added in XmlTest during AlterSuiteListener not available in SuiteListener (C.V.Aditya)
 Fixed: GITHUB-2296: Fix for assertEquals not working for sets as order is not guaranteed. (Prashant Maroti)

src/main/java/org/testng/reporters/EmailableReporter2.java

@@ -344,7 +344,7 @@ private int writeScenarioSummary(
               .append("<td rowspan=\"")
               .append(resultsCount)
               .append("\">")
-              .append(start)
+              .append(getFormattedStartTime(start))
               .append("</td>")
               .append("<td rowspan=\"")
               .append(resultsCount)
@@ -389,6 +389,10 @@ private int writeScenarioSummary(
     return scenarioCount;
   }
 
+  protected String getFormattedStartTime(long startTimeInMillisFromEpoch) {
+    return String.valueOf(startTimeInMillisFromEpoch);
+  }
+
   /** Writes the details for all test scenarios. */
   protected void writeScenarioDetails() {
     int scenarioIndex = 0;