Cron job for time sync

15 * * * 5 /usr/sbin/ntpdate us.pool.ntp.org >/dev/null 2>&1
20 * * * 5 /sbin/hwclock --systohc >/dev/null 2>&1

1 2	15 * * * 5 /usr/sbin/ntpdate us.pool.ntp.org >/dev/null 2>&1 20 * * * 5 /sbin/hwclock --systohc >/dev/null 2>&1