Analysis of information sources in references of the Wikipedia article "Frederick William Franz" in English language version.
The Watchtower said that Brother Franz was baptized April 5, 1914. Brother Splane said he was baptized in November of 1913. ... in the 1960s ... some who knew Brother Franz ... assumed that April 5, 1914, would've been the date. Well, Brother Franz was in his 70s at the time and so he just accepted the suggested date. ... after his life story, a personal copy of Brother Franz's Daily Heavenly Manna was found in an old suitcase of his. And it dated from 1913. And under the date of November 30, ... Brother Franz wrote ... "I was baptized symbolically into Jesus' death this afternoon in Chicago, Illinois."