Centos 7 time
On Centos/RHEL 7 the time is usually set using the Chrony daemon.
Over at Cert Depot you'll find a fine explanation of how to set the time. Jump down to the Chrony part. After stuggling several hours I realised that ntpd will not work correctly on the newer releases for some odd reason.
Basicly all you have to do is to install chrony
root ]$ yum install chrony
The enable the package to run and start it
]$ systemctl enable chronyd ]$ systemctl start chronyd ]$ chronyc sources -v
the latter command give you a good overview of if the chrony is working as expected.