The Rev. Canon Dr. Scott Sharman, Ecumenical and Interfaith Coordinator, has prepared a reference sheet for some of the main religious observances within the Jewish, Muslim, Hindu, Sikh, and Buddhist communities. It offers brief descriptions of the meanings and sentiments connected with these occasions and celebrations, as well as sample templates for greetings that could be shared on behalf of churches and/or church leaders. The document can be found in the Ecumenical and Interfaith Ministry Resources section of the diocesan website. Inter-religious Greetings for Holy Days and Festivals
Another helpful source is this Online Calendar.