Equation of time and analemmic curve

Excerpt from the author's foreword: This is a book about an equation; about a single equation and its two thousand years of history. The topics presented in the chapters of this book are scattered throughout a wide variety of literature, so this book is merely an attempt to combine pieces of content which together form a historical and astronomical concept which we today call the equation of time. Unlike many professional books written by experts with solid knowledge in certain fields of expertise, this book is a scrapbook of records that I compiled when I studied the history and theory of the equation of time. I hope this fact does not reduce the useful value of the book. ... The reader will be able to learn about the history of the equation of time, be acquainted with its calculation, but will also be able to study more demanding cases of calculating the equation of time, which are useful for astronomic purposes. Sundial enthusiasts will also find in the book the expressions for the graphic design of sundials and analemmic curves. If I manage to pique the interest of the reader to the extent that they engage in practical applications of the material presented, for example, designing sundials, my purpose is achieved, and the effort entirely worthwhile.