change datetime format for EventTimeStamp

Author: ankitkumarr

src/WebJobs.Script.WebHost/Diagnostics/EventGenerator.cs

@@ -11,11 +11,11 @@ namespace Microsoft.Azure.WebJobs.Script.WebHost.Diagnostics
 {
     internal class EventGenerator : IEventGenerator
     {
-        private const string EventTimestamp = "MM/dd/yyyy hh:mm:ss.fff tt";
+        private const string EventTimestampFormat = "O";
 
         public void LogFunctionTraceEvent(TraceLevel level, string subscriptionId, string appName, string functionName, string eventName, string source, string details, string summary, string exceptionType, string exceptionMessage, string functionInvocationId, string hostInstanceId, string activityId)
         {
-            string eventTimestamp = DateTime.UtcNow.ToString(EventTimestamp);
+            string eventTimestamp = DateTime.UtcNow.ToString(EventTimestampFormat);
             FunctionsSystemLogsEventSource.Instance.SetActivityId(activityId);
             switch (level)
             {
@@ -36,7 +36,7 @@ public void LogFunctionTraceEvent(TraceLevel level, string subscriptionId, strin
 
         public void LogFunctionMetricEvent(string subscriptionId, string appName, string functionName, string eventName, long average, long minimum, long maximum, long count, DateTime eventTimestamp)
         {
-            FunctionsSystemLogsEventSource.Instance.LogFunctionMetricEvent(subscriptionId, appName, functionName, eventName, average, minimum, maximum, count, ScriptHost.Version, eventTimestamp.ToString(EventTimestamp));
+            FunctionsSystemLogsEventSource.Instance.LogFunctionMetricEvent(subscriptionId, appName, functionName, eventName, average, minimum, maximum, count, ScriptHost.Version, eventTimestamp.ToString(EventTimestampFormat));
         }
         public void LogFunctionExecutionAggregateEvent(string siteName, string functionName, long executionTimeInMs, long functionStartedCount, long functionCompletedCount, long functionFailedCount)
         {