Joseph expressed plans to dedicate himself to translation between 1835 and 1842.
Memorial to Nauvoo High Council, June 18, 1840, The Joseph Smith Papers website, accessed May 7, 2021
[H]e [Joseph Smith] thinks and verily believes that in the time has now come when he should devote himself exclusively to those things which relate to Spiritualities of the church and commence the work of translating the ejyptian Records.