I have never read any threads on this topic before, which I guess means I'm the first person to make this mistake.. But, I had always heard people talking about their 11:30am PATs and such, and I just assumed I would get an e-mail or something in the mail prior to the cruise letting me know when to arrive.. I was wrong. It was getting closer and closer to cruise time so I decided to call customer service to find out when our PAT was..
I was notified that you can't get a port arrival time until you fill out/upload all the online things: flights, ID's, credit card info. Until then the Port Arrival Time would remain grayed out.
As quickly as possible I filled everything out copy and pasting from Southwest and all that, adding my credit card and sure enough the "Port Arrival Time" button was now available! But of course the earliest times were all taken and 1PM is when we will be arriving... I know there are some people that prefer later times because you miss the hustle and bustle, but we are trying to spend every minute possible on that awesome ship!
Live and learn, I guess this is just a rookie mistake that I obviously wont make when we go on our 2nd/3rd cruises and so on. But, hopefully me posting about my mistake will help newbies in the future get the earliest times possible.