The Yartzeit the Torah tells us about.

This upcoming Shabbos presents a unique event: a meeting between the weekly Torah Parsha and the date of the day itself; we will read in the Torah about the very day on which the Parsha is being read. This Shabbos will be Rosh Chodesh Av, and in the Parsha we will read about the death of Aharon, which occurred “in the fifth month, on the first of the month”—on Rosh Chodesh Av.This rare alignment invites us to explore the enigma of Aharon’s yahrzeit: What merit did Aharon have to be the only person in the entire Tanakh—throughout thousands of years of history—whose date of death is explicitly stated in the Torah?The Tanakh does not record the death dates of any of humanity’s great figures - not Avraham nor Sarah, not Yoseph nor David. Now although we do know many of their yahrtziets by inference or calculations, but the Torah itself does not mention them - besides for one exception: Aharon’s death.This exception becomes even more intriguing when we consider where the Torah chooses to mention the date of Aharon’s death: in our portion, even though it has no relevance to the portion’s content.