"When it is 9am in Vancouver, on the west coast it's 1:30pm." This is the only sentence that makes sense.
"...on the west coast it's 1:30pm" is the subject clause. This is the main point of the whole sentence; adding "when" to the other clause marks that action as a reference point in time.
This was a bit tricky, as both pieces of information can be considered as "equal status".