biber.tex

\usepackage[autostyle]{csquotes}
\usepackage[
	backend=biber,
	style=authoryear,
	sortlocale=de_DE,
]{biblatex}
\addbibresource{Literaturverzeichnis.bib}
\DeclareNameAlias{sortname}{first-last}

\DeclareFieldFormat{url}{\newline\url{#1}}
\newbibmacro*{url+urldate}{%
 \printfield[url]{url}%   
 \iffieldundef{urlyear}     
 {}     
 {\setunit*{\addspace}%      
 \printtext{\printurldate}}}

\DeclareLabeldate{%
  \field{date}
  \field{eventdate}
  \field{origdate}
}

\renewbibmacro*{date+extradate}{%
  \ifboolexpr{test {\iffieldundef{labelyear}}
    or (test {\iffieldequalstr{labelyear}{nodate}}
        and test {\ifentrytype{online}})}
    {}
    {\printtext[parens]{%
       \iflabeldateisdate
         {\printdateextra}
         {\printlabeldateextra}}}}

\renewbibmacro*{cite:labeldate+extradate}{%
  \ifboolexpr{test {\iffieldundef{labelyear}}
    or (test {\iffieldequalstr{labelyear}{nodate}}
        and test {\ifentrytype{online}})}
    {}
    {\printtext[bibhyperref]{\printlabeldateextra}}}