Library /sys$common/syshlp/nclhelp.hlb update, dtss  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Gradually adjusts the clock on the specified server node to a new
    time, beginning at the time specified by the Time argument.

    update [node node-id] dtss time [absolute-time]

    Example:

    update dtss time 1996-12-30-11:24:00.000-05:00I02.000