How to format datetime indicator in Unity's panel to show in two lines?

Is it possible to format datetime indicator in Unity3D to show in two lines? I tried this:

how-to-customize-indicator-datetime-to-two-line-configuration

But that seems to work only when I run my Ubuntu 11.04 in classic mode. When using Ubuntu with Unity3D this command shows itself in the panel and nothing is formated. I figured out that I can make it to show in two lines with "%n" between date and time but then font is too big and indicator is not fully visible.

Any idea how to format or at least change the font size?