The easiest way to handle leap seconds is with the <acronym>POSIX</acronym> time rules FreeBSD uses by default, combined with <link xlink:href="@@URL_RELPREFIX@@/doc/en_US.ISO8859-1/books/handbook/network-ntp.html"><acronym>NTP</acronym></link>. When <citerefentry><refentrytitle>ntpd</refentrytitle><manvolnum>8</manvolnum></citerefentry> is running and the time is synchronized with upstream <acronym>NTP</acronym> servers that handle leap seconds correctly, the leap second will cause the system time to automatically repeat the last second of the day. No other adjustments are necessary.