/sys$common/syshlp/helplib.hlb SET, DIRECTORY, Qualifiers, /BEFORE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /BEFORE[=time]

    Selects only those directories dated prior to the specified
    time. You can specify time as absolute time, as a combination
    of absolute and delta times, or as one of the following keywords:
    BOOT, LOGIN, TODAY (default), TOMORROW, or YESTERDAY. Specify
    one of the following qualifiers with the /BEFORE qualifier
    to indicate the time attribute to be used as the basis for
    selection: /BACKUP, /CREATED (default), /EXPIRED, or /MODIFIED.

    For complete information on specifying time values, refer to the
    OpenVMS User's Manual or the online help topic DCL_Tips (subtopic
    Date_Time).