title: How to trigger notification from firebase at a specific time?
body: <p>I am doing a fitness app in which I have to notify the user at a specific time from the date I have stored in firebase.</p>
  
  <p>For example: I am saving a today's timestamp in firebase DB say "start_at":"timestamp", now I have to send a notification after 1 week from the date(timestamp) I stored.</p>
  
  <p>It is similar to cron feature. I don't know exactly how to achieve it in firebase.</p>
  
  <p>Is Anyone there to help me?</p>