I tried to find links to several online resources that cover a wide diversity of the ethnic groups in the US, especially those that include ethnic holidays (such as Chinese New Year) along with religious holidays.
- InterfaithCalendar.org – a web site listing many religions and a long-term calendar. Includes links to explanations about religious traditions.
- University of Washington’s Calendar of Religious Holidays and Observance
- When Is: Dates of religious and civil holidays around the world
- Religion and Ethics Weekly (PBS) Multi-faith Calendar