for theologians, clergy, and students of religious studies." "The opening of "Heortology" introduces the concept of sacred time and festivals, emphasizing their significance in expressing worship through designated days for rest and reflection. It discusses the long-standing tradition across religions of dedicating time to the divine and the establishment of Christian holy days, particularly focusing on the origins of the ecclesiastical calendar derived from Jewish traditions. In this introductory section, the author outlines the structure of the work and the importance of meticulously categorizing and studying the various festivals, laying the groundwork for a deeper exploration of themes that connect Christian worship practices with their historical and theological roots." (This is an automatically generated summary.)