To cite package ‘countdown’ in publications use:

Aden-Buie G (2025). countdown: A Countdown Timer for HTML Presentations, Documents, and Web Apps. R package version 0.6.0.9000, https://github.com/gadenbuie/countdown.

Corresponding BibTeX entry:

  @Manual{,
    title = {countdown: A Countdown Timer for HTML Presentations,
      Documents, and Web Apps},
    author = {Garrick Aden-Buie},
    year = {2025},
    note = {R package version 0.6.0.9000},
    url = {https://github.com/gadenbuie/countdown},
  }