The user Torbjørn T. has posted a nice approach on how to display the names of the days of the week in dateplots.
Minimum Working Example (MWE):
\documentclass{standalone}
\usepackage{pgfplots}
\usepackage{filecontents}
\usepgfplotslibrary{dateplot}
\begin{filecontents}{data.csv}
Date; Value
2019-04-01 12:00:00; 1
2019-04-02 12:00:00; 2
2019-04-03 12:00:00; 3
2019-04-04 12:00:00; 4
2019-04-05 12:00:00; 5
\end{filecontents}
\newcount\tmpCnt
\begin{document}
\begin{tikzpicture}
\begin{axis}[date coordinates in = x,
xmin = 2019-04-02 12:00:00,
xticklabel = \pgfcalendardatetojulian{\year-\month-\day}{\tmpCnt}\pgfcalendarjuliantoweekday{\tmpCnt}{\tmpCnt}\pgfcalendarweekdayshortname{\tmpCnt},
xtick distance = 1,
table/col sep = semicolon]
\addplot table[x=Date,y=Value]{data.csv};
\end{axis}
\end{tikzpicture}%
\end{document}
Screenshot of the result:
Question:
How to change the English language formats to German language formats? E.g. weekday "Tue" should be displayed as "Di" for "Dienstag".
I have already tried the following approaches, unfortunately without success:
\documentclass[german]{standalone}\usepackage[ngerman]{babel}\usepackage{ngerman}

