doc: improve description of refclock tai option

Emphasize that tzdata must be kept up to date in order for the
correction to work as expected.

diff --git a/doc/chrony.conf.adoc b/doc/chrony.conf.adoc
index c6702ea7040cc8f2772b3e1044562c530d6b8222..dfacfc9e6bb05640393e0842dcfdbc1f7e63014e 100644 (file)
--- a/doc/chrony.conf.adoc
+++ b/doc/chrony.conf.adoc
@@ -550,12 +550,11 @@ unauthenticated NTP sources in order to improve the accuracy of the clock. They
 can be selected and used for synchronisation only if they agree with the
 trusted and required source.
 *tai*:::
-This option indicates that the time on the given reference clock is kept in TAI
-instead of UTC and that *chronyd* should apply the current TAI-UTC offset to
-samples taken from this refclock. To use this, the *leapsectz* directive must
-be used as *chronyd* uses the timezone files to compute the TAI-UTC offset.
-This option does not make sense if the given refclock is only being used for
-PPS input.
+This option indicates that the reference clock keeps time in TAI instead of UTC
+and that *chronyd* should correct its offset by the current TAI-UTC offset. The
+<<leapsectz,*leapsectz*>> directive must be used with this option and the
+database must be kept up to date in order for this correction to work as
+expected. This option does not make sense with PPS refclocks.
 *minsamples* _samples_:::
 Set the minimum number of samples kept for this source. This overrides the
 <<minsamples,*minsamples*>> directive.