The Battle of the Titans. Shulchan Aruch HaRav vs Aruch Hashulchan.
Rabbi Mendel Krasnjanski
Source Sheet History of Halachic Seforim through the ages Can you make up for missed Tefilos? How far back can you make up? Which Amida should you do first? How do you make up for a day with Ya'aleh V'yavo?