CentOS Timing Synchronization System time

Use Linux.vps the next day, found that the system time is incorrect, manual modification or synchronization of the correct once, run half a day to find time and fast a few minutes, anyway, the longer it runs, the faster, is the VPS through?

and VPS Manager communication without fruit, and then search the Internet after the decision to use the timer automatic synchronization time calculation.

SSH execution Command:
#crontab-E
Add a line after execution: (as with the VI command, press I to enter edit mode, ESC returns to the command mode: w Save changes: Q exit)
*/30 * * * * /usr/sbin/ntpdate asia.pool.ntp.org >>/var/log/crontab.log 2>&1
The number 30 represents 30 minutes of execution, and after saving and exiting, it is also necessary to restart the timer task.
#service crond Restart

The following >>/var/log/crontab.log indicates that the timed execution is written to the log file to make it easy to see if there are any exceptions.

Note Utpdate to write the full path, some people on the Internet do not write the full path will cause the following exception:
/bin/sh:ntpdate:command not found

If your Linux system doesn't ntpdate this command at all,

Yum Install NTP

CentOS Timing Synchronization System time