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22.17. Configuring the Hardware Clock Update

To configure the system clock to update the hardware clock, also known as the real-time clock (RTC), once after executing ntpdate, add the following line to /etc/sysconfig/ntpdate:
SYNC_HWCLOCK=yes
To update the hardware clock from the system clock, issue the following command as root:
~]# hwclock --systohc
When the system clock is being synchronized by ntpd, the kernel will in turn update the RTC every 11 minutes automatically.