Kabbalistic books written hundreds of years ago and even thousands of years ago present tables of mutual positions of the sun, the moon, the Earth, Venus, Mars and the other planets. The Hebrew calendar, which has been used for many generations, is based on this information and does not need any corrections.
All the holidays, special astronomical dates, the beginning of the month, the eclipse of the moon, the eclipse of the sun, and the positions of the planets in relation to each other, etc. are determined and take place on the same day of the year. What is more, this was determined many years in advance.
I don’t know the exact date that the Hebrew calendar was created, but I believe that it is thousands of years old and is still working like clockwork today. It indicates precisely when, in which year, a certain holiday will be celebrated and a certain event, for example, will occur only on a Sunday or a Wednesday.
Can this calendar be changed? No, Kabbalists understand so well how the upper forces that manage our planet’s work that they created this calendar as the eternal calendar. Its uniqueness is that it is related both to the sun and the moon.
The Muslim calendar is focused only on the moon, and the Christian calendar is focused only on the sun. The Hebrew calendar is focused on both the sun and the moon because according to the wisdom of Kabbalah every motion, the whole philosophy of life, is arranged according to the middle line.
From the Kabbalah Lesson in Russian 8/14/16