After the team travels to 1891 to deal with the alien, and learns that Stapleton has the whistle that's the only thing capable of taming the creature, Nate suggests going to a square dancing contest held that day at noon to get near Stapleton in order to get the whistle. A flyer Nate found advertising the dance says the contest will take place Friday, April 30. However, in 1891, April 30 was a Thursday. Also, a poster in the saloon references another event happening on Saturday, March 3 when in 1891 March 3 was a Tuesday. Even worse, it is impossible for a Saturday March 3 and a Friday April 30 to exist in the same calendar year.