Changes the value of, or recalibrates, the system time.
    On Alpha and Integrity server systems, this service accepts 64-
    bit addresses.
    Format
      SYS$SETIME  [timadr]
    C Prototype
      int sys$setime  (struct _generic_64 *timadr);
1 – Argument
 timadr
    OpenVMS usage:date_time
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by 32- or 64-bit reference (Alpha and Integrity
                  servers)
    New absolute time value for the system time, specifying the
    number of 100-nanosecond intervals since 00:00 o'clock, November
    17, 1858. The timadr argument is the 32- or 64-bit address (on
    Alpha and Integrity server systems) of a quadword containing the
    new system time value. A negative (delta) time value is invalid.
    If you do not specify the value of timadr or specify it as 0,
    $SETIME recalibrates the system time using the time-of-year
    clock.