title: Firebase Cloud Functions - Delete Entries where timestamp field is over a month old and run daily
body: <p>This is a two in one question.</p>
  
  <p>Part 1:
  I am storing data in Firestore, and one of my fields is an 'end_date' timestamp field.
  How can I write a cloud function, so that when this field is over a month in the past, the record is deleted?</p>
  
  <p>Part 2:
  How can I get this to run every day?</p>