Execution function time is not match with the scheduled job time

We have scheduled TriggerdNotitication() function at 12.10.10PM

Expected would be TriggerdNotitication() will be executed at 12.10.10PM
But Actual TriggerdNotitication() is executed at 12.10.25PM

Version: 1.8.2

why this taken extra 15 sec sometimes its increase to 20sec sometimes its 14 sec it is not exact match with scheduled time

we have found this major issue as notification is delay instead within 1min it sent around 45sec or 40 sec

TimeZoneInfo siteTZ = TimeZoneInfo.FindSystemTimeZoneById(SiteClient.SiteTimeZone);
    scheduleTime = TimeZoneInfo.ConvertTime(scheduleTime, TimeZoneInfo.Utc, siteTZ);
     scheduleTime = scheduleTime.AddHours(HelperMethods.GetHangireAWTimeZoneOffset());

     //Removing ACP-> PerItemItem from scheduled time
      scheduleTime = scheduleTime.AddMinutes(-Convert.ToDouble(perItemTiggerTime));
      BackgroundJob.Schedule(() => TriggerdNotitication(eventID, triggerTime), scheduleTime);

Hangfire jobs aren’t actually scheduled. The date/time specified is just when the job becomes available on the queue. There could be other jobs ahead of it or depending on your polling frequency, there could be a delay for when the job is actually processed. If you need very strict scheduling I would suggest using something specific for it, like Quartz.net

Found the solution reduced the default queueing time 15 seconds to 5seconds

    new Hangfire.SqlServer.SqlServerStorageOptions
    { QueuePollInterval = TimeSpan.FromSeconds(5) });

app.UseHangfireServer(new BackgroundJobServerOptions()
    SchedulePollingInterval = TimeSpan.FromSeconds(5).