Please explain the customs concerning Yahrtzeit observance in leap years. If someone died in a regular Adar year, some rabbis say one needs to keep it in both Adars of a leap year. This seems cruel and puzzling. Others disagree (no surprise here I guess) so what is the prevalent Ashkenaz Psak?

A Yahrtzeit (not on the first year where there are laws of eleven or twelve months) Spharadim and Ashkenazim have diferent customs. If the person passed away on a regular year the Rma (Ashkenazim) writes to observe the Yahrtzeit on the first Adar, and the Shulchan Aruch to observe it on the second. If it was on the first Adar of a leap year, all agree that on leap years it should be observed on the first Adar. Rabbi Ro'i Margalit