title: celery for different timezones
body: <p>Now I using django-celery to send scheduled emails to user. it works fine if all users in same timezone. But if a user in different timezone, he will get the not in right time.</p>
  
  <p>For example, I scheduled an email send to user a, user b at 8am every day with CrontabSchedule, server is GMT time, user a is GMT, user b is GMT+1, user a will get that email at 8am but user b will get it at 9am.</p>
  
  <p>How can I schedule tasks for different timezones with celery?  </p>