title: hosted service (background service) in asp.net core restart in each Publish azure
body: <p>I have a hosted service that sends an email each 3 days
  my problem is when I publish in azure the service restart the calculation of 3 days</p>
  <pre><code>  public Task StartAsync(CancellationToken cancellationToken)
          {
  
              _timer = new Timer(SendReminderEmail, null, TimeSpan.FromDays(3), TimeSpan.FromDays(3));
               
  
              return Task.CompletedTask;
          }
  </code></pre>
  <p>there is a solution to this problem? for example, I publish sure azure Tuesday I expect I have an email Friday but if I publish another time in azure Wednesday it will calculation from Wednesday :/</p>
  <p>thank you</p>