Holidays and festivals are included for select religious, ethnic and public communities. Even here, the list is not exhaustive of the observances of any one religion. For example, regional and ethnic holidays and observances of faith traditions are not included, nor, for the most part, are the traditional holidays celebrated by tribal groups. In cases where these are included, they serve more than one group.

Teachers may find the calendar particularly helpful as it identifies opportunities for objective, non-creedal instruction about particular cultures. Employers will find that it serves as a reminder of those religious observances that may result in employee absences. Those using this calendar also should remember that it is based only on information available at the time of production. Dates for lunar holidays are subject to change.