Everybody keep in mind that all the shipping companies (USPS, FedEx, UPS, DHL, etc) have a major increase in volume right about now. That means there's often an extra day or two involved, despite any ETA they might initially provide. I deal with shipping rather often and almost every one in the past week or two has had some type of minor delay.
I'd add a day or two to the estimate. Better to be surprised if it arrives on time than disappointed if it doesn't.