addressing timezones, this is mostly well covered by
.BR tzset (3).
One area that seems to have no documentation is the 'right'
-directory of the Time Zone Database, aka tz, aka zoneinfo.
+directory of the Time Zone Database, sometimes called tz or zoneinfo.
.PP
There are two separate databases in the zoneinfo system, posix
and 'right'. 'Right' (now named zoneinfo\-leaps) includes leap seconds and posix
-does not. To use the 'right' database the System Clock must be kept in
-\%UTC\ +\ leap_seconds, i.e., \%TAI\ \-\ 10. This allows calculating the
+does not. To use the 'right' database the System Clock must be set to
+\%(UTC\ +\ leap seconds), which is equivalent to \%(TAI\ \-\ 10). This
+allows calculating the
exact number of seconds between two dates that cross a leap second
epoch. The System Clock is then converted to the correct civil time,
including UTC, by using the 'right' timezone files which subtract the