Use timeline library with months

Question

I'm trying to adapt this answer to a timeline that has months instead of years. The first part of the MWE below is just the timeline library.

\documentclass[tikz]{standalone}
% Timeline library
\usetikzlibrary{backgrounds,calc}
\usepackage{xstring}

\pgfkeys{/tikz/.cd,
  timespan/.store in=\timespan,
  timespan=Week,
  timeline width/.store in=\timelinewidth,
  timeline width=20,
  timeline height/.store in=\timelineheight,
  timeline height=1,
  timeline offset/.store in=\timelineoffset,
  timeline offset=0.15,
  initial week/.store in=\initialweek,
  initial week=1,
  end week/.store in=\endweek,
  end week=2,
  time point/.store in=\timepoint,
  time point=0.5,
  between week/.style args={#1 and #2 in #3}{
    initial week=#1,
    end week=#2,
    time point=#3,
  },
  involvement degree/.store in=\involvdegree,
  involvement degree=2cm,
  phase color/.store in=\phasecol,
  phase color=red!50!orange,
  phase appearance/.style={
    circle,
    opacity=0.3,
    minimum size=\involvdegree,
    fill=\phasecol
  },
}
\pgfkeys{/tikz/milestone/.cd,
  at/.store in=\msstartpoint,
  at=phase-1.north,
  circle radius/.store in=\milestonecircleradius,
  circle radius=0.1cm,
  direction/.store in=\msdirection,
  direction=90:2cm,
  text/.store in=\mstext,
  text={},
  text options/.code={\tikzset{#1}},
}

\newcommand{\reftimespan}{\MakeLowerCase{\timespan}}

\newcommand{\timeline}[1]{
  \draw[fill,opacity=0.8] (0,0) rectangle (\timelinewidth,\timelineheight);
  \shade[top color=black, bottom color=white,middle color=black!20]
    (0,0) rectangle (\timelinewidth,-\timelineoffset);
  \shade[top color=white, bottom color=black,middle color=black!20]
    (0,\timelineheight) rectangle (\timelinewidth,\timelineheight+\timelineoffset);

  \foreach \smitem [count=\xi] in {1,...,#1} {\global\let\maxsmitem\xi}
  \pgfmathsetmacro\position{\timelinewidth/(\maxsmitem+1)}
  \node at (0,0.5\timelineheight)(\timespan-0){\phantom{Week 0}};

  \foreach \x[count=\xi] in {1,...,#1}{
      \node[text=white]at +(\xi*\position,0.5\timelineheight) (\timespan-\xi) {\timespan\ \x};
  }
}

\newcounter{involv}
\setcounter{involv}{0}

\newcommand{\phase}[1]{
\stepcounter{involv}
\node[phase appearance,#1]
(phase-\theinvolv)
at ($(\timespan-\initialweek)!\timepoint!(\timespan-\endweek)$){};
}

\newcommand{\initialphase}[1]{
\node[phase appearance,#1,anchor=west,between week=0 and 1 in 0,]
(phase-\theinvolv)
at ($(\timespan-0)!0!(\timespan-1)$){};
\setcounter{involv}{0}
}

\newenvironment{phases}{\begin{pgfonlayer}{background}}{\end{pgfonlayer}}

\newcommand{\addmilestone}[1]{
\pgfkeys{/tikz/milestone/.cd,#1}
\draw[double,fill] (\msstartpoint) circle [radius=\milestonecircleradius];
\draw(\msstartpoint)--++(\msdirection)node[/tikz/milestone/text options]{\mstext};
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


% redefinition for having a interval not starting from 1
\renewcommand{\timeline}[1]{
  \draw[fill,opacity=0.8] (0,0) rectangle (\timelinewidth,\timelineheight);
  \shade[top color=black, bottom color=white,middle color=black!20]
    (0,0) rectangle (\timelinewidth,-\timelineoffset);
  \shade[top color=white, bottom color=black,middle color=black!20]
    (0,\timelineheight) rectangle (\timelinewidth,\timelineheight+\timelineoffset);

  \foreach \smitem [count=\xi] in {#1}  {\global\let\maxsmitem\xi}
  \pgfmathsetmacro\position{\timelinewidth/(\maxsmitem+1)}
  \node at (0,0.5\timelineheight)(\timespan-0){\phantom{Week 0}};

  \foreach \x[count=\xi] in {#1}{
      \node[text=white]at +(\xi*\position,0.5\timelineheight) (\timespan-\xi) {\timespan\ \x};
  }
}

\begin{document}

\begin{tikzpicture}[timespan={},% empty to not display a label before the month
  between month/.style args={#1 and #2 in #3}{% auxiliary style for month
    initial week=#1,
    end week=#2,
    time point=#3,
  }
  ]
\timeline{August,September, October, November, December, January, February,
  March, April, May, June, July} % months

% put here the phases
\begin{phases}
\phase{between month=1 and 10 in 0.2,involvement degree=4cm}
\phase{between month=3 and 7 in 0.5,phase color=blue!80!cyan}
\end{phases}

% put here the milestones
\addmilestone{at=phase-2.110,direction=120:1.5cm,text={Testing milestone text},text options={above}}
\end{tikzpicture}
\end{document}

Edit: Using the updated version of the timeline libray the names of the months in the following MWE are wrongly aligned and too close one to another. The other thing that I would like to achieve is to say something like

\phase{between week=1 and 7 in 0.5,involvement degree=4cm}

and have the phase (bubble) cover the whole distance between the starting and endpoints.

\documentclass[tikz]{standalone}

\input{timeline_library.tex}

\begin{document}
\begin{tikzpicture}[timespan={}]

\timeline[custom interval=true]{August, September, October, November, December,
  January, February, March, April, May, June, July}

\begin{phases}
\initialphase{involvement degree=1.75cm,phase color=black}
\phase{between week=1 and 7 in 0.5,involvement degree=4cm}
\end{phases}

\addmilestone{at=phase-0.90,direction=90:1cm,text={Initial meeting},text options={above}}
\end{tikzpicture}
\end{document}

Answer 1

The new version of the library can use custom time intervals. As a result, it is now possible to set up a timeline with the names of the months:

\timeline[custom interval=true]{January, March, May, July, September, November}

A complete example:

\documentclass[border=10pt]{standalone}

\usepackage{tikz}
\usetikzlibrary{timeline}

\begin{document}

\begin{tikzpicture}[timespan={}]% no label is displayed for the timespan

\timeline[custom interval=true]{January, March, May, July, September, November}

% put here the phases
\begin{phases}
\initialphase{involvement degree=1.75cm,phase color=black}
\phase{between week=1 and 2 in 0.1,involvement degree=2.25cm}
\phase{between week=1 and 2 in 0.5,involvement degree=3cm}
\phase{between week=1 and 2 in 0.9,involvement degree=2.125cm}
\phase{between week=3 and 4 in 0.7,phase color=blue!80!cyan}
\end{phases}

% put here the milestones
\addmilestone{at=phase-0.90,direction=90:1cm,text={Initial meeting},text options={above}}
\addmilestone{at=phase-0.270,direction=270:1cm,text={Initial meeting},text options={below}}

\addmilestone{at=phase-2.110,direction=120:1.5cm,text={Research},text options={above}}
\addmilestone{at=phase-2.250,direction=240:1.5cm,text={Need Agreement},text options={below}}
\end{tikzpicture}

\end{document}

The result:

For what concern the vertical alignment, a text depth was missing since the labels were not supposed to be pure text at the beginning. It is fixed in version 0.3a of the library.

For what concern the other point, I will show how to change shape and to use the between month option (basically an alias of between week): so far it is not possible to draw a rectangle from month 1 to month 7, but one has to play with the key involvement degree to find the correct setting. Why? Very simple. To a TikZ node you can only specify the minimum width and nodes are needed to be able to deploy milestones. To have nodes' width to be of a given width, one has to measure things and at the moment I don't have time to implement this feature. It is a nice suggestion, though, so it will be implemented in the near future.

The code:

\documentclass[border=10pt]{standalone}

\usepackage{tikz}
\usetikzlibrary{timeline}

\begin{document}

\begin{tikzpicture}[timespan={},timeline width=25]

\timeline[custom interval=true]{August, September, October, November, December,
  January, February, March, April, May, June, July}

% put here the phases
\begin{phases}
\initialphase{involvement degree=1.75cm,phase color=black}
\tikzset{phase appearance/.append style={
  rectangle, 
  minimum width=\involvdegree,
  minimum height=3cm}
}
\phase{between month=1 and 7 in 0.5,phase color=green!80!black,involvement degree=12cm}
\end{phases}

% put here the milestones
\addmilestone{at=phase-0.90,direction=90:1cm,text={Initial meeting},text options={above}}
\addmilestone{at=phase-0.270,direction=270:1cm,text={Initial meeting},text options={below}}
\addmilestone{at=phase-1.270,direction=270:1cm,text={A big achievement},text options={below}}
\end{tikzpicture}

\end{document}

The result: