Why isn't Abram Leibowitz's Yahrzeit Exact?

We do not know the exact date of death of Abram Leibowitz. According to Jewish tradition, if the exact date of death is not known, the yahrzeit of a person can be observed on any day, as long as it is that same day every year. Since that is the case, we observe the yahrzeit of Abram Leibowitz on 11 Sivan. If you know the exact date of death of Abram Leibowitz, contact us via the contact page. Be sure to include the url: https://eachofushasaname.org/person/3344/Abram_Leibowitz.html