One solution is to redefine the macro cite:labelyear+extrayear
to always wrap the labelyear
(and extrayear
, if applicable) in parentheses.
\renewbibmacro*{cite:labelyear+extrayear}{%
\iffieldundef{labelyear}
{}
{\printtext[parens]{%
\printtext[bibhyperref]{%
\printfield{labelyear}%
\printfield{extrayear}}}}}
This will make \textcite
and \citeyear
look weird though, so we can also go for a slightly longer redefinition of the cite
macro (along with a definition of a new macro):
\newbibmacro*{cite:labelyear+extrayear:paren}{%
\iffieldundef{labelyear}
{}
{\printtext[parens]{\usebibmacro{cite:labelyear+extrayear}}}}
\renewbibmacro*{cite}{%
\global\boolfalse{cbx:loccit}%
\iffieldundef{shorthand}
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}
{\usebibmacro{cite:ibid}}
{\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
{\usebibmacro{cite:label}%
\setunit{\addspace}}
{\printnames{labelname}%
\setunit{\nameyeardelim}}%
\usebibmacro{cite:labelyear+extrayear:paren}}}
{\usebibmacro{cite:shorthand}}}
or (to put everything into one macro)
\renewbibmacro*{cite}{%
\global\boolfalse{cbx:loccit}%
\iffieldundef{shorthand}
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}
{\usebibmacro{cite:ibid}}
{\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
{\usebibmacro{cite:label}%
\setunit{\addspace}}
{\printnames{labelname}%
\setunit{\nameyeardelim}}%
\iffieldundef{labelyear}
{}
{\printtext[parens]{\usebibmacro{cite:labelyear+extrayear}}}}}
{\usebibmacro{cite:shorthand}}}
MWE with the second solution
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{csquotes}
\usepackage[backend=bibtex, style=authoryear-ibid, autocite=footnote]{biblatex}
\addbibresource{biblatex-examples.bib}
\newbibmacro*{cite:labelyear+extrayear:paren}{%
\iffieldundef{labelyear}
{}
{\printtext[parens]{\usebibmacro{cite:labelyear+extrayear}}}}
\renewbibmacro*{cite}{%
\global\boolfalse{cbx:loccit}%
\iffieldundef{shorthand}
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}
{\usebibmacro{cite:ibid}}
{\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
{\usebibmacro{cite:label}%
\setunit{\addspace}}
{\printnames{labelname}%
\setunit{\nameyeardelim}}%
\usebibmacro{cite:labelyear+extrayear:paren}}}
{\usebibmacro{cite:shorthand}}}
\begin{document}
Lorem\autocite[Vgl.][123]{markey} ipsum\autocite{knuth:ct:a} dolor\autocite{knuth:ct:b} sit\autocite{knuth:ct:a,knuth:ct:b} amet.
\Textcite{wilde} consecetur.
\printbibliography
\end{document}