I have my TimeMachine backup in two drives. I need one drive for other use, so i must stop using it for my TM backup. Searching inside its folders I've found that the two drives share backups of the same days. For example, both have a backup folder of the 5th of June 2015. This leads me to think that if i format the drive i want to release from Time Machine then the shared backup folders will be deleted and i probably will lose those backups! What can i do? Is it possible to merge the backups of the drive i need with the backups of the second drive that is used by TimeMachine and if so, what do i do?