I am trying to set a DISPLAY for oclock and everything I try does not work.
I am on Red Hat 7.0 using bash
Any thoughts??

If you really mean Red Hat 7.0, the first thought would be you need to upgrade...RH 7 is ANCIENT. But chances are you mean Red Hat ENTERPRISE Linux 7.0, right?

You don't actually tell us what, exactly, you've done/tried, where you tried it, and what you mean by "does not work"...read the "Question Guidelines" link in my posting signature. Without details, we can't even begin to help you. Tell us what you did, what the results were, and what your actual goal is. Also, why are you using Red Hat Enterprise 7.0?? That's designed for servers, and it's a commercial, pay-for distro. Are you paying for RHEL?

You shouldn't need to set it.

With a GUI login, the GUI sets it. If you force it (via .profile or such initialization) then you will likely set the wrong value.

By default, the display for the FIRST login is :0.0. A second concurrent login will get :1.0

A remote login via ssh with X forwarding enabled on the server (and either set on the client, or requested by the client) will get a unix:10.0, or localhost:10.0, depending on various configurations of the server.

In any of these cases, setting the DISPLAY to something else will cause failures.

By default, X is configured to be as secure as possible. Thus the GUI disables the use of TCP for window connections. Instead it uses domain sockets, controlled by access permissions, and authorization keys. In this mode, remote X connections will fail. The preference is to use ssh with forwarded X connections.