Cacher is the code snippet organizer for pro developers

/*
Auto delete backupfiles in folder older than 30 days
Fill in the folder id found in the drive url
And keep a good structure with mulitple clients

- [Backups]
 -- client name
 -- client name
 -- client name

Stephan Zuidberg
www.amrz.nl

*/

function getSubFolders(parent) {
    parent = parent.getId();
    
    var childFolder = DriveApp.getFolderById(parent).getFolders();
    
    while (childFolder.hasNext()) {
    
        var child = childFolder.next();
        
        getSubFolders(child);
      
    }
    return;
}

function removeAkeebaBackupFiles() {
    
    var parentFolder = DriveApp.getFolderById("------FOLDER ID------");
    var childFolders = parentFolder.getFolders();

    while (childFolders.hasNext()) {
        
        var child = childFolders.next();

        getSubFolders(child);

        var folder = DriveApp.getFolderById(child.getId());
        var files = folder.getFiles();
        var ThirtyDaysBeforeNow = new Date().getTime() - 3600 * 1000 * 24 * 30;
        var cutOffDate = new Date(ThirtyDaysBeforeNow);
        var cutOffDateAsString = Utilities.formatDate(cutOffDate, "GMT", "yyyy-MM-dd");

        while (files.hasNext()) {
          
            var file = files.next();
            var getDateCreated = Utilities.formatDate(file.getDateCreated(), "GMT", "yyyy-MM-dd");

            if (cutOffDateAsString > getDateCreated) {
                
                try {
                    file.setTrashed(true);
                    Logger.log("Send to Trash: " + file.getName() + " Owner is " + file.getOwner());

                } catch (e) {
                    // Only owners can trash
                    Logger.log("Unable to Trash: " + file.getName() + "Owner is " + file.getOwner());
                }
               
            }
        }
    }
}