Conversation so far:
when were the white cliffs of dover formed
The white cliffs of dover were formed 100 million years ago.
how were the white cliffs of dover formed
Cliffs are formed as erosion landforms by the processes of weathering and erosion.
why were the white cliffs of dover important
Crossing at Dover was the primary route before the advent of air travel, the white line of cliffs also formed the first or last sight of Britain for travellers.
how far are the white cliffs of dover from san jose, ca
The distance from San Jose to White Cliffs of Dover is 5,423 mi.

Question: what's the travel duration
Self-contained rewrite: what's the travel duration by from the white cliffs of dover to san jose, ca