Edited Claims- what date priority?

Question

On an old Non-provisional, if the patent owner keeps revising claims based on alternative embodiments and gets them granted,

What priority date do the new granted claims have? Old priority date or when the new claims are granted ?

Ex: Patent owner patents a walking teddy bear toy with alternative embodiments of walking pandas, and walking insects in 2000.

He is granted claims of a walking teddy bear. Claims date back to 2000.

In 2015 a walking grasshopper toy is all the rage.

Patent owner deletes all claims on teddy bear and goes to revise all the patent claims to walking insects hoping to encompass the grasshopper toy.

If granted, will the manufacturer of the walking insect toy be liable from 2015 or 2000 if claims are granted?

Answer 1

You are mixing two concepts there.

Priority: is in short the date up to which prior art publications can invalidate a claim. The priority date of the claim will be 2000. A publication from 2005 cannot invalidate the claim. (The claim needs to be fully supported by the original description though.)

Provisional rights: As I explained in this answer, someone can be sued for infringing a patent application after it is granted and retrospectively, if and only if, they had notice of the application and the claims didn't substantially change (In the US, similar provisions, see linked answer, exist in other countries). Therefore if the claims are substantially changed, damages/royalties are owned only after the grant, if the manufacturer stops all "would-be-infringing" actions by then, they are not liable for patent infringement.