Abstract
Official month names in Estonian and other Finnic languages (except for Finnish), as well as in many other languages, originate from Latin. In addition to these, folk names are also used; these date back to long before the emergence of the Christian calendar and currently appear as parallel variants in calendars, fiction, and specialised literature. The aim of this study is to provide a comprehensive overview of Finnic folk month names, their distribution, structure, origin, and naming principles. To achieve this, an extensive body of material was analysed, ranging from the earliest documentations of folk month names to contemporary treatments, while also incorporating all available dictionaries, lexicons, archival materials, and similar sources. The article examines the underlying reasons for these specific month names, whether they overlap across different languages, whether regional variations emerge based on cultural background, and how they have evolved over time. The study reveals that folk month names in Finnic languages can exhibit a high degree of semantic overlap, as they are based on the same naming principles. Furthermore, names related to nature and labour are predominantly indigenous, whereas those derived from feast days contain a substantial proportion of loanwords. To facilitate a better understanding of word formation, the paper also addresses the history of time reckoning and the events that have influenced the naming of months.