Kalendar – Thoreau’s term for phenological phenomena of a local ecology. That being New England.

Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate.

The scientific study of periodic biological phenomena, such as flowering, breeding, and migration, in relation to climatic conditions. See https://en.wikipedia.org/wiki/Phenology

Between 1860 and 1862, the final years of his life, Henry David Thoreau attempted to consolidate the detailed observations of seasonal change recorded in the later years of his Journal in a variety of lists and charts he sometimes referred to as his “Kalendar.”

Check out this impressive body of work cataloging Thoreau’s work in this area of science. The menu is the “pancake” icon at the upper left side of the website.

Visit Thoreau’s Kalendar – https://thoreauskalendar.org/about.html