Backup of Office 365 for staff
When you delete items (including OneDrive, Shared Library files) from a SharePoint site, they're sent to the site Recycle Bin (also called the first-stage Recycle Bin), where you can restore them if you need to.
 
When you delete items from a site Recycle Bin, they're sent to the site collection Recycle Bin (also called the second-stage Recycle Bin), where they stay for the remainder of the 93 days. SharePoint Online retains backups of all content for 14 additional days beyond actual deletion. If content cannot be restored via the Recycle Bin or Files Restore, an administrator can contact Microsoft Support to request a restore any time inside the 14-day window.
 
In addition to Microsoft's default backup, a second level backup is performed by a 3rd party backup software in following schedule:
 

Email Backup

  • By default: User can recover deleted items within 30 days
  • Backup staff email accounts in Microsoft Office 365
  • Daily backup + Weekly backup on Sunday
  • Retention policy
    • Daily repository: 14 days
    • Weekly repository: 1 year

 

SharePoint Backup

  • By default: User can recover deleted items within 93 days
  • Backup departmental SharePoint sites in Microsoft Office 365
  • Weekly backup on Saturday
  • Retention policy
    • SharePoint repository: 1 year