There are many dates that claim when Kabbalah started. So to really answer the question we have to choose a few different opinions.
In the book of Raziel the angel it’s written that Kabbalah began after Adam and Eve were kicked out from the Garden of Eden.
According to other opinions Kabbalah began during the time of Abraham the Patriarch as he discovered the unification of all Gods, what we call in our time quantum physics.That everything is actually one and there is no difference. So to refer to when Kabbalah began, if we are talking about Kabbalah as a wisdom, or as a philosophy of life, or what the Kabbalists refer to the Tree of Life or the Flower of life, we know that it is written in the book of Genesis that after Adam and Eve ate from the forbidden fruit of the Tree of Knowledge, God was concerned that they would approach the Tree of Life and live forever.
There is no explanation of what exactly is the Tree of Life, what was the fruit of the Tree of Life , and what exactly was God’s concerns over Adam and Eve living forever.
The explanation by all Kabbalists, is that once they are from the forbidden fruit of the Tree of Knowledge their consciousness and awareness went down dramatically.
The talmud describes that that drop of consciousness was similar in a physical description as if Adam, who was bigger than the biggest dinosaur and then he shrank to the size that we are familiar with today. Try to use this as a visual for the concept of spirituality.
When God said I don’t want Adam and Eve to live forever, God meant that he doesn’t want us as humans to live in the consciousness of the Tree of Knowledge forever. It wasn’t that God didn’t want us to live a long life, the opposite , God wanted us to live a long life with the right consciousness. Which is the idea that we can receive as much as we want for the sake of sharing not for the sake of just benefiting our ego.
Going back to the original question and refer to a time, if we refer to the Book of Abraham then Kabbalah began about 4000 years ago. If we refer to the book of Raziel the angel who was together with Adam and Eve when they were kicked out of the Gardneb of Eden then we relate to the Jewish year that is related to the birth of Adam and Eve, which is 5779.