{* *! version 1.0.0  12may2011}{...}
    {cmd:dofh(}{it:e_h}{cmd:)}
{p2colset 8 22 26 2}{...}
{p2col: Domain {it:e_h}:}{cmd:%th} dates 0100h1 to 9999h2
           (integers -3,720 to 16,079){p_end}
{p2col: Range:}{cmd:%td} dates 01jan0100 to 01jul9999
           (integers -679,350 to 2,936,366){p_end}
{p2col: Description:}returns the {it:e_d} date (days since 01jan1960) of
           the start of half-year {it:e_h}.{p_end}
{p2colreset}{...}
