One of the oddities about Kabbalah is that its students often play more attention to the day a person died than they do to the person's birthday.
(Obviously, I am talking about dead people and not the living.)
The reason for this is the fact that in Kabbalah, the day of one's death is considered to be the day that your energy is released into the universe.
The seed of your energy is planted on the day of your conception; it breaks into view on the day of your birth; it grows (or declines) as you live your life; and finally, it is released on the day of your death.
The day of your death is the summation of your entire life. The day a holy man (or woman) dies is a blessing given to the entire world. Their last breath is an act of redemption for the entire world.
Now, the happy little cynic that I am will note that this belief probably is a spiritualization of a practical solution of a common problem. Sometimes it is easier to use the death day as a marker for your studies than a birthday.
For many famous and important people, we have no record of the date of their birth. Birthdays were only for royalty and other important people.
Commoners did not keep track of such matters; heck, in medieval times, children were considered much like we consider interchangeable parts---if one child dies, you can always have another one to replace them. You did not become attached to a child until it proved that it was strong enough to survive. Harsh times produce hardened hearts.
Those people who started out as commoners often did not know their own birthdays, and the only reason we know the death date for many famous people is, well, they became famous and important and someone thought the event was important enough to write down.
And the happy little cynic in me says that it was while studying the lives of those who become famous, but started out ordinary, that Kabbalah became more interested in the death day than birthdays for its holy men.
It is something that I have often noticed. One of the layers of kabbalah, ignored much like we ignore the physical layer of Golden Dawn ritual (the symbolic is all that matters to many students), is the practical. Often a practical issue or solution will be assigned a spiritual reason later. The expulsion of the Jews from Spain ended up being embedded in the concept of the Jews being chosen to spread out all over the world in order to redeem it. The kosher laws were to prevent them from mingling with other people (there were also [probably] dietary reasons for the kosher laws). The list probably could go on for pages and days.
In the Western world, we have examples of death days being remembered (and to a certain extent celebrated): JFK, Martin Luther King, Elvis, Michael Jackson, et cetera. Many of us (if not all) have experienced the emotional impact of the death of someone. If you remember where you were when you heard the news, you were one of the blessed.