SET_FUPDT #channel [,time] or
SET_FUPDT \file [,time]
The command SET_FUPDT sets the date on which a file was last altered. This is always set to the current system DATE when a file is SAVEd, or CLOSEd after having been written to. If time is not specified (or is 0), then the current DATE is used. If time is set to 1, then this command will have no effect on the file. COPY sets the update time on the file being created to the current DATE. For a SuperBASIC ‘backup’ function which gives the newly created file the same update time as the original and alters the backup time, see FBKDT. This command supports the current default data directory (see DATAD$).
If you use SET_FUPDT to alter the update time of a file OPENed to the specified channel, closing that channel later in the program will not affect the update time.