To cite package ‘theRefdate’ in publications use:

  Lueers P (2026). _theRefdate: Simple and Fast Date Manipulation on
  Character Strings in Format 'DD.MM.YYYY'_. R package version 1.0.0,
  <https://CRAN.R-project.org/package=theRefdate>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {theRefdate: Simple and Fast Date Manipulation on Character Strings in Format
'DD.MM.YYYY'},
    author = {Prem Lueers},
    year = {2026},
    note = {R package version 1.0.0},
    url = {https://CRAN.R-project.org/package=theRefdate},
  }