Ok here's the final timeline I've made after rereading the entire canon and making notes on dates. This does not apply to any fanfic I've written, which play by their own rules. This is just what I've worked out from the Holmes stories themselves, but attempting to make chronological sense. I will use the four-letter abbreviations by Jay Finley Crist, to save typing.
In the "Adventures" stories, Holmes and Watson keep referring between cases as if they happened in order, but I ignore those references as Watson self-promoting, just like in SIGN he keeps referring to STUD as if it was recent, rather than years ago, and pretends that the Baker Street Irregulars haven't aged. As I said before, Watson lies out of discretion. In SPEC for example, Watson specifically states that he could not publish it until after the lady (Helen Stoner) died. In other cases, the principle people have not yet died, so Watson could be changing names and dates out of discretion for the clients. That's the only way to make GLOR make sense, that Watson substituted the Crimean War from 1855 instead of a war from 1845, so that the real Victor Trevor cannot be identified. Holmes could have asked Watson to do so, for the sake of his college friend.
Even if we assumed that Watson was honest, the dates would not make sense. For example, Watson claims that SCAN occurred on March 20, 1888, then he leaves IDEN undated other than a reference to the King of Bohemia some weeks ago. But REDH refers to Mary Sutherland's case (that is, IDEN) being just "the other day" even though REDH is in autumn 1890. How can IDEN be just weeks after March 1888, yet just "the other day" before 1890? (Unless there was some second case for the King of Bohemia, in 1890, for which Holmes accepted a gaudy snuffbox for payment.) Thus these references between stories can't be relied upon. It's dramatic license pretending that Holmes is commenting as each story is published. Holmes after all faked his death in May 1891, and Watson published the short stories starting in July 1891, after the presumed death.
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