If you specify the [DATE] variable in the archive name, the file name of each backup will include that backup’s creation date.
When using this variable, the first backup of a new day will be a full backup. Before creating the next full backup, the software deletes all backups taken earlier that day. Backups taken before that day are kept. This means you can store multiple full backups with or without incremental ones, but no more than one full backup per day. You can sort the backups by date. You can also use a script to copy, move, or delete the older backups.
The value of this variable is the current date surrounded by brackets ([]). The date format depends on the regional options on the machine. For example, if the date format is year-month-day, the value for January 31, 2012, is [2012-01-31]. Characters that are not supported in a file name, such as slashes (/), are replaced with underscores (_).
You can place this variable anywhere in the archive name. You can use both lowercase and uppercase letters in this variable.
Examples
Example 1. Suppose that you perform incremental backups twice a day (at midnight and noon) for two days, starting on January 31, 2012. The archive name is MyArchive-[DATE], the date format is year-month-day. Here is the list of backup files after day two:
MyArchive-[2012-01-31].tib (full, created on January 31 at midnight)
MyArchive-[2012-01-31]2.tib (incremental, created on January 31 at noon)
MyArchive-[2012-02-01].tib (full, created on February 1 at midnight)
MyArchive-[2012-02-01]2.tib (incremental, created on February 1 at noon)
Example 2. Suppose that you perform full backups, with the same schedule, archive name, and date format as in the previous example. Then, the list of backup files after day two is the following:
MyArchive-[2012-01-31].tib (full, created on January 31 at noon)
MyArchive-[2012-02-01].tib (full, created on February 1 at noon)
This is because the full backups created at midnight were replaced by new full backups of the same day.