R. Zimmerman also wrote Agan ha-Sahar (New York 1954) his Magnum Opus on one of the most difficult subjects in Halacha, the international time zone. His work is pure genius. It was said about him that he understood quantum theory as well as did Niels Bohr when most of the scientific community had scarcely heard of it yet. Binyan Halakha (New York 1942) novellae to the Rambam's Mishne Torah. His responsa were published in Hamaor, contemporary rabbinical journal.