In Centos, how does one permanently modify the system time?

In Centos, how does one permanently modify the system time?

When Centos is used, if the local time is not correct, the command date-s "15:15:15" takes effect immediately. However, after the system is restarted, the system time remains the same.

Find the information and make a summary.

My Centos is installed on a virtual machine. The virtual machine has the sub-system time and hardware time. One of the changes is that there is no way to work, and both must be changed.

1.Date{View current local time}

2.Hwclock -- show{View hardware time}

3. If the hardware time is not correct, modify the hardware time,

4.Hwclock -- set -- date '014-12-15 15:15:15'{Set hardware time}

5.Hwclock -- hctosys{Set system time and hardware time synchronization}

6.Clock-w{Save clock}

7. Restart the instance,Init 6After a quick restart, check whether the system time has taken effect !!!! 1