1917, Cairo - British Major Archibald Talbot antagonizes a trio of Egyptian-looking men at a cafe, incurring a curse upon his bloodline that will make his descendants prey to all manner of supernatural predators. Two weeks later, he disappears.
1920 - Major Talbot's mummified remains are delivered to the British Museum, without explanation.
1946 - One of Major Talbot's grandchildren is found burned to death outside his fire-destroyed house. It's unclear if the fire killed him, as he'd returned home from World War II with an inexplicable aversion to sunlight.
30 years before Ghoul Goblin, Sheriff Dagget is elected to his position in Boone Mill, which he'll hold without interruption until Ghoul Goblin.
1987 - Cynthia Cedar becomes a junior attache to the U.S. Embassy in Cairo.
1988 - Exploring ancient crypts as a tourist, Cynthia Cedar and her local guide are attacked by animated mummies. The pair are saved by the guide's Qarin -- a guardian angel-like jinn -- which transports Cynthia safely back to her residence, and remains with her as her secret lover until Ghoul Goblin.
15 years before Ghoul Goblin, Cynthia Cedar is elected Mayor of Boone Mill, a position she'll hold for the next decade and a half.
"Weeks" after Fool Moon, Harry encounters and wounds (possibly kills) a humanoid fish-creature in Lake Michigan, which he fails to identify. Two days later, sheriff's deputy Prescott Tremaine hires him to look into two mysterious deaths in Boone Mill, Missouri.
During Ghoul Goblin, Bob complains that he hasn't been "out" of his skull for almost a year.
During Ghoul Goblin, Harry has his first encounter with a ghoul in Boone Mill. (Probably also his first encounters with a goblin, a naga, or a qarin, but it's not specified as such.)
Three of the five Talbots of the current generation are killed during the Ghoul Goblin investigation, and Mayor Cedar's qarin lover forfeits his power and freedom to protect the youngest two. Griswald the goblin and Ambre the ghoul are destroyed. Harry Dresden utilizes the qarin's parting gift of power to end the bloodline curse, sparing Ella and TJ from their siblings' fate. Mayor Cedar and Prescott Tremaine assume responsibility for the two young Talbots' upbringing.
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That seems to be it, where dates from GG are concerned.
Note that there's one obvious dating discrepancy in the Ghoul Goblin comic: at one point, Deputy Tremaine says that Mayor Cedar was elected in '98, which contradicts Cedar's own remark that she's been running the town for 15 years. As other commentary suggests that she ran for office very soon after returning from Egypt, it seems likely that this is a math error: Butcher must've subtracted 15 from the year when he wrote Ghoul Goblin, temporarily forgetting that it was set shortly after Fool Moon and thus, needed to be backdated a bit.
