\usemodule[gantt]
%\usemodule[gantt][alternative=mp]
%\usemodule[gantt][alternative=tikz]
\setuppagenumbering[location=]

\starttext
  \startgantt{7}{12}
    \startganttitle
      \numtitle{1}{1}{12}{1}
    \stopganttitle
    \ganttbar{a task}{0}{2}
    \ganttbarcon{a consecutive task}{2}{4}
    \ganttbarcon{another consecutive task}{8}{2}
    \ganttbar{another task}{2}{2}
    \ganttbar{another task}{4}{2}
    \ganttbar{another task}{4}{2}
    \ganttcon{4}{4}{4}{6}
  \stopgantt
\stoptext
