To cite package ‘openholidaysR’ in publications use:

  Feldhege J (2025). _openholidaysR: Provides Access to the
  'OpenHolidays' API_. R package version 0.1.0,
  <https://github.com/jfeldhege/openholidaysr>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {openholidaysR: Provides Access to the 'OpenHolidays' API},
    author = {Johannes Feldhege},
    year = {2025},
    note = {R package version 0.1.0},
    url = {https://github.com/jfeldhege/openholidaysr},
  }