The default command execution history 
of how the execution time plus the command of it, here we must use HISTTIMEFORMAT variable, the following is a temporary modification, after the system restart will fail
[root@centos7-test ~]# export HISTTIMEFORMAT="%F %T whoami "
The result of executing the history command again is as follows: It 
takes effect permanently. It needs to be written to the configuration file, which can be written to the profile in the user's home directory. Use source to make the configuration take effect.
Restart the host and verify whether it is successful. 
If all users take effect, you need to write to /etc/profile and then source /etc/profile.