Looks like everything now is come after I needed them..
No, but from the seller's point of view it is better to promise December 15 and have something delivered December first than to promise December first and have it delivered December second.
That being said, you have 30 days after the last estimated date to open an Item Not Received dispute.
Hmm-- There should be two dates, but I think if one has passed the default is just to show the later one. That may be the reason you see a 'later'date.
It always was there, but you, naturally focussed on the earlier one.
Personally, I allow 20 days for delivery from North America and 30 days from Asia, from the shipping date (or the payment date if I don't get a tracking* number).
Paypal allows buyers to open Disputes fairly soon after payment, without worrying about delivery dates. You have 180 days after payment to dispute through Paypal.
Whether your seller is in North America or Asia, it is about time to open a PP dispute.
*Tracking is a Seller Protection. It does nothing in particular for the buyer but irritate.