The book "Remarks on the solar and lunar years, the cycle of 19 years, commonly known as the golden number, the epacta, and the method of finding the date of Easter, as it is now done in most countries of Europe" by George Parker Macclesfield, Earl of. This book describes the complex mathematical and astronomical teaching related to the calculation of the solar and lunar calendars, as well as the methods of determining the date of the celebration of Easter in various European countries. The author reveals important aspects of the calculations that formed the basis of the modern calendar used in most countries of the world. The book is intended for those who are interested in the history of the development of the calendar system and astronomy.