To cite package ‘era’ in publications use:

  Roe J (2024). _era: Year-Based Time Scales_. R package version
  0.5.0.9000, , <https://github.com/joeroe/era>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {era: Year-Based Time Scales},
    author = {Joe Roe},
    year = {2024},
    note = {R package version 0.5.0.9000, },
    url = {https://github.com/joeroe/era},
  }