All files are backup up. Backup is retained for 35 days. This is called a cumlative incremental backup. Backup is retained for 35 days.
Backup starts every day shortly after midnight and runs for a few hours.
Reader File Retention Periods Files residing in a user's reader will remain for a predefined number of days, based on the type of file. Job returned from MVS is deleted after 05 days. Personal mail is deleted after 15 days. Mailing list is deleted after 05 days. Any other file is deleted after 08 days.