Question: What are the dates and catalog numbers for the US and UK releases of Younger Than Yesterday? 
Answer: Younger Than Yesterday was released on February 6, 1967 in the United States (catalogue item CL 2642 in mono, CS 9442 in stereo) and April 7, 1967 in the UK (catalogue item BPG 62988 in mono, SBPG 62988 in stereo).