Chronosys package

Question

I have been using chronosys for a few days now, and some problems have arisen. I have modified the file chronosyschr.tex to delete the reference to a year 0 that does not exist

\!chrdefaultstartyear chrdefaultstartyear{1}!chrdefaultstopyear chrdefaultstopyear chrdefaultwidth chrdefaultwidth chrdefaultwidth{\the\textwidth}%.

So, if you want a timeline with the BEC and EC centuries, the year 0 always appears :

\documentclass[11pt,a4paper,landscape]{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usepackage{chronosys}

\begin{document}
     \begin{chronology}[align=left, startyear=-400, stopyear=500, height=1cm, startdate=false, stopdate=false,arrowheight=0.75cm,arrowwidth=0.75cm]
     \chronograduation[periode][dateselevation=0pt]{100}
     \end{chronology}
\end{document}

Two another questions:

• How to make a timeline with important values (billions of years)?
• How to draw a fine line around each period or a block of periods?

Thanks a lot!