This is a follow-up to this question and the requirement for Plain TeX is still in place.
I am trying to create the effect of floating a string (date) above the long underscore I create using the first method in the accepted answer.
This is the closest I have come, but obviously the underline does not match up with the underscore.
Date \hskip 1 pt \underbar{12-25-2014} \vrule height .4pt width 7cm


\hssdo? I've never heard of this command before. – Svend Tveskæg Dec 26 '14 at 11:56\hfillin LaTeX – Dec 26 '14 at 11:59\hssandhfillare both primitives so also defined in latex,\hfillonly has stretch component, not shrink\hsshas both. – David Carlisle Dec 26 '14 at 13:08\underline. This may not be available in plain tex. – merlin2011 Dec 26 '14 at 17:22$...$? it is a math command – Dec 26 '14 at 18:32