The CES Letter claims that Joseph Smith and Oliver Cowdery "backdated and retrofitted Priesthood restoration events."
Jeremy Runnells, CES Letter: My Search for Answers to my Mormon Doubts, self-published online, 2017, p. 83
It wasn’t until the 1835 edition Doctrine & Covenants that Joseph and Oliver backdated and retrofitted Priesthood restoration events to an 1829-30 time period – none of which existed in any previous Church records; including Doctrine & Covenants’ precursor, Book of Commandments, nor the original Church history as published in The Evening and Morning Star.