ATTENTIONATTENTION:

Please make sure that you read /usr/local/share/doc/clockspeed/INSTALL.
It contains important information about testing and configuring
clockspeed, and finally installing it in your system.

Clockspeed uses the libtai library, check /usr/ports/devel/libtai
for more details. TAI time measure is off 22 seconds from UTC time
measure. Therefore, your system time will show a 22 secs difference
from your time source after you've installed this port.

To fix this, you could follow this simple recipe created with
PR ports/27617.

1) killall clockspeed (you can't have it running)
2) sntpclock IP.OF.NTP.SERVER | clockadd
3) enable/start clockspeed :
	% cp /usr/local/etc/rc.d/clockspeed.sh.sample \
	  /usr/local/etc/rc.d/clockspeed.sh
	# enable clockspeed to automagically start next
	# time you reboot. do this after testing everything
	% /usr/local/etc/rc.d/clockspeed.sh start
	# start clockspeed now
4) sntpclock IP.OF.NTP.SERVER > /usr/local/etc/clockspeed/adjust
5) cd /usr/src/share/zoneinfo
6) make -DLEAPSECONDS clean all install ; make clean

Step 5 and 6 build support in your system for leapseconds handling.
Take a note about this since you might forget later to disable it
if you remove this port. To disable it, simply re-do step 6 without
-DLEAPSECONDS.
Step 6 should not break anything but you can disable it anytime
as per last paragraph if you think something unusual has happened
to your system.
 
7) /stand/sysinstall -> configure -> time zone (choose the correct
   time zone for your system)
8) sntpclock IP.OF.NTP.SERVER | clockview

Check how close is your clock before and after now. Should be
within milliseconds.

Do not forget to add a cron(8) job with step 4 to periodically
adjust clockspeed's drift rate. Once a week should be more than
adequate.

A port to non-i386 platforms was done using the clock_gettime(2)
function. Since this is somewhat experimental, there might be some
tiny precision differences from the i386 platform versions. You
have been warned!