Backups - Is the following possible to achieve with TI?

I am just starting out with True Image, and can't find a way to tune the backup schedules the way I want.

I need to backup my files every two days (incremental or differential is fine for this), and I don't want to retain these backups for longer than six days. So far, the only way I've found to do this is to create a schedule to run the job every two days, and then to set 'Create a new full backup after' to be 6 days.
However, my problem with this is that it takes several hours to create full backup so I'd rather not do this every 6 days.

Is there some way I can:
Create a full-backup.
Then schedule a differential every two days.
Once a differential becomes more than six days old, automatically delete it.
Every thirty days, start again with a full-backup.

Any help much appreciated!