vertical alignment of parbox one below the other

Question

I want to align all the parboxes vertically so that the left corners are are equally offset from the dates which are in the left side

\documentclass{article} 
\usepackage{enumitem}
\usepackage{geometry}
\usepackage{xcolor}
\usepackage{tabularx}
\renewcommand*\familydefault{\sfdefault}


\begin{document}
                \begin{center}{\large \textbf{HANDING / TAKING OVER}}\end{center}
            \begin{description}         

\item AON for CHT
\subitem 11 Nov 2019--\parbox{\textwidth}{Preetha check progress with IFA}
\subitem 12 Nov 2019--\parbox{\textwidth}{Preetha to liaise with IFA}
\subitem 14 Nov 2019--\parbox{\textwidth}{ IFA has asked to come on next Wednesday}

\item Video Conferencing with ADGQA
\subitem 13 Nov 2019--\parbox[t]{\textwidth}{ pts for discussion}
\subsubitem Padmavathy for Digital DGQA--\parbox[t]{\textwidth}{She will be available for guidance but Kannan should take over \\--if required he can got to Bangalore}
\subsubitem Component Level Repair CLR--\parbox[t]{\textwidth}{  83 items\\{-- }to be decided by CQAL, Bangalore\\Action by Debnath}
\subsubitem FR 56j--\parbox[t]{\textwidth}{  List upto Jun 2020 to be sent \\{--}list again faxed on 14 Nov 2019\\ Vishwanath case--decision already conveyed as told by Col Vibhor}
\subsubitem Cover assembly BMP--\parbox[t]{\textwidth}{  2017 pending?\\ FFT?\\ Delay to be pinpointed \\Delay in G1 Form? \\Action by Kambli}
\subsubitem Digital DGQA--\parbox{\textwidth}{  Action by  --Kannan}
\end{description}
\end{document}

EDIT: Re @Johannes_B:not compiling Just ran it and it compiles--throwing up the image below from screen capture

And the code says No Error No Warningssee below

Answer 1

I took the liberty of aligning the -- dividers. I got the 20pt and 30pt from the definitions of \subitem and \subsubitem in article.cls.

\documentclass{article} 
\usepackage{enumitem}
\usepackage[showframe]{geometry}% use showframe for debugging only
\usepackage{xcolor}
\usepackage{tabularx}
\renewcommand*\familydefault{\sfdefault}

\newlength{\datewidth}
\settowidth{\datewidth}{\begin{tabular}{@{}l@{}}% overkill
  11 Nov 2019-- \\
  12 Nov 2019-- \\
  14 Nov 2019-- \\
  13 Nov 2019--
\end{tabular}}
%\settowidth{\datewidth}{22 Nov 2019--}% IIRC 2 is the widest digit

\newcommand{\myitem}[2]% #1 = date, #2 = text
  {\subitem \makebox[\datewidth][r]{#1}\parbox[t]{\dimexpr \linewidth-\datewidth-20pt}{#2}}
\newcommand{\mysubitem}[2]% #1 = heding, #2 = text
  {\sbox0{#1}\subsubitem \usebox0\parbox[t]{\dimexpr \linewidth-\wd0-30pt}{#2}}

\begin{document}
                \begin{center}{\large \textbf{HANDING / TAKING OVER}}\end{center}
            \begin{description}         

\item AON for CHT
\myitem{11 Nov 2019--}{Preetha check progress with IFA}
\myitem{12 Nov 2019--}{Preetha to liaise with IFA}
\myitem{14 Nov 2019--}{ IFA has asked to come on next Wednesday}

\item Video Conferencing with ADGQA
\myitem{13 Nov 2019--}{ pts for discussion}
\mysubitem{Padmavathy for Digital DGQA--}{She will be available for guidance but Kannan should take over \\ \llap{--}if required he can got to Bangalore}
\mysubitem{Component Level Repair CLR--}{  83 items\\ \llap{--}to be decided by CQAL, Bangalore\\Action by Debnath}
\mysubitem{FR 56j--}{  List upto Jun 2020 to be sent \\ \llap{--}list again faxed on 14 Nov 2019\\ Vishwanath case--decision already conveyed as told by Col Vibhor}
\mysubitem{Cover assembly BMP--}{  2017 pending?\\ FFT?\\ Delay to be pinpointed \\Delay in G1 Form? \\Action by Kambli}
\mysubitem{Digital DGQA--}{  Action by  --Kannan}
\end{description}
\end{document}