CentOS Time Out of sync network problem

The newly installed CentOS system server may be incorrectly configured, and the time zone needs to be adjusted. The following is the CentOS system using NTP to synchronize from a time server:
The first step : Adjust the current time zone to Shanghai is +8 district, want to change other time zone can also go to see/usr/share/zoneinfo directory;
Cp/usr/share/zoneinfo/asia/shanghai/etc/localtime
Step two : Synchronize Standard Time with Ntpdate
Ntpdate us.pool.ntp.org
Note: There is no installation of ntpdate can Yum: Yum install-y ntpdate

CentOS Time Out of sync network problem