Even allowing for the possibility of time passing between the end of the movie and the beginning of the series, this firmly places the characters in the post-Victorian world. How, then, can this date be reconciled with the clues in the animated feature? Jane's dress is clearly Victorian, and she anticipates meeting the Queen herself, who died in 1901.

The only possible explanation is that the Porters are completely out of touch with the rest of the world. Buried in scientific pursuits, they are unmindful of clothing trends or unwilling to keep up with them, resulting in Jane as a fashion "don't". They are also blissfully ignorant of politics.

Perhaps it was only the years of intense effort required to bring about their African expedition that caused Jane's absent-mindedness (one assumes that Porter is always so). In that case, once settled in the jungle, the Porters can presumeably keep a bit more abreast of current events via wireless and week-old newspapers at Dumont's trading post.