When did the U.S. Mint start using dated hubs to make working dies?

Does anybody have a link to a reference that can confirm WHEN the U.S. Mint started using dated hubs to sink working dies with the dates already on them, thus eliminating the need to hand punch dates into working dies?
It is my understanding that the new gold designs of 1907 and 1908 had dated hubs, and that the technique was phased in on other denominations. What I need to know is, when was it phased in? At the start of 1908 on some denominations, in the middle of the year on others, or what?
Bill Fivaz confirmed to me that some 1908 cent and dime dies show varieties caused by hand punching dates.
Any hep would be appreciated.
TD
Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
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D. Carr might know...
I knew it would happen.
It was done in 1853 for several silver denominations.
http://www.seateddimevarieties.com/date_mintmark/1853wavarpage.htm
But perhaps you meant to ask "When did they switch to this technique permanently?"
An interesting question, and I have no answer, so here is a BTT in hopes someone can help.
Yes, an interesting question !!!
Yes, because of the great recoinage of silver at the new weights, when they needed so many dies that it was cost effective to make a dated hub that they would use for one year and then discard.
Obviously in modern times the coinage had increased to the point that the demand for dies justified the use of dated hubs. I am just trying to pin down exactly when this transition took place. Did it take place during 1908 or after 1908, starting in 1909. That is the question I need answered.
Does anybody have the Mint Report for 1908 and/or 1909 in their library?
Need an answer on the 1908 dating. Any ideas?