clockspeed(1)                                                    clockspeed(1)



NNAAMMEE
       clockspeed - speed up or slow down the local clock, continuously

SSYYNNOOPPSSIISS
       cclloocckkssppeeeedd

DDEESSCCRRIIPPTTIIOONN
       cclloocckkssppeeeedd resets the local UNIX clock every three seconds according to
       (1) an internal hardware tick counter and (2) occasional real-time mea-
       surements from a reliable source.

       cclloocckkssppeeeedd  reads  the  real-time  measurements  from //uussrr//llooccaall//cclloocckk--
       ssppeeeedd//aaddjjuusstt.  Each real-time measurement  must  be  a  single  16-byte
       packet, expressed as a TAI64NA time adjustment to the local UNIX clock.

       cclloocckkssppeeeedd does not place any limits on the possible  adjustments.   It
       is your responsibility to make sure that the measurements are reliable.

       After two real-time measurements, cclloocckkssppeeeedd can figure out the  number
       of  real  attoseconds per tick.  It saves this number in TAI64NA format
       in   //uussrr//llooccaall//cclloocckkssppeeeedd//eettcc//aattttoo,   overwriting    //uussrr//llooccaall//cclloocckk--
       ssppeeeedd//eettcc//aattttoo..ttmmpp   for   reliability.    It  reads  //uussrr//llooccaall//cclloocckk--
       ssppeeeedd//eettcc//aattttoo when it starts up again.

       cclloocckkssppeeeedd must be run by rroooott.

SSEEEE AALLSSOO
       clockadd(1), clockview(1), sntpclock(1), taiclock(1), adjtime(2),  get-
       timeofday(2)



                                                                 clockspeed(1)