ETA start and end meaning and accuracy

Hello. Been reading the ordering process threads, along with the time tables, and I was wondering (a) what the ETA "start" and "end" dates mean and (b) if they mean estimated time of arrival to the dealer, are they usually accurate?

I ordered a 2018 screw in magnetic with beadlocks on 10/7 and got the VIN on 10/13. I thought it took much longer to get the VIN....? I get an update every Friday from my dealer and the last shows that it will be built on 11/20 and then ETA Start Date: 12/16 and ETA End Date: 12/22. What are these dates?

Thanks

http://www.fordraptorforum.com/f260/tracking-your-new-order-%96-step-step-faqs-51142/

Read up muchacho

The ETA thing sounds new. Ford may be providing a window now... keep us posted

Mine had a window of delivery of 10/23-10/29 showed up to me dealer on the 25th. So they got it pretty good IMO.