time‑unit[D|H|M]
12H
Purpose
The PurgeFileAge parameter specifies the length of time since a read‑only file was last modified before it is purged from the defined virtual directory for that application; for example, PurgeFileAge=7M.
The parameter value is a time‑unit numeric, optionally followed by a modifier D (days), H (hours), or M (minutes). The D multiplier multiplies by 86,400; the H multiplier multiplies by 3,600; the M multiplier multiplies by 60; and all other time‑unit values are treated as seconds. Specify zero (0) if you want to turn off the purging of the physical directory.
The minimum time-unit value that you can specify is 30 seconds; the maximum value is 365D (days). Values outside this range are forced to their respective limits.
This parameter applies only if the VirtualDirectory parameter has a specified value, and only files that match the PurgeDirectoryRule parameter criteria are considered (that is, all non‑read‑only files or by default, standard files of type .jpg, .png, or .gif that are more than the specified age).