Are you flying United or Continental this weekend? Betcha didn’t know that the now merged companies are planning on shifting all of their computer systems over on Saturday, with the potential to affect thousands of passengers in a very unfun way. Including yours truly, who happens to be flying Continental on Sunday.

Portfolio.com goes over the basics of the switch, starting Saturday morning at 1.a.m, which involves United ditching the system they’ve used for 40 years and starting up with Continental’s instead. In turn, all Continental flights will become United, its site will redirect to United.com, and its ticket numbers starting with 005 will go the way of the dinosaur.

So what does this mean for you if you’re flying this weekend or next week? Well, simply put, it might get ugly. Past moves of this type, including the merger of US Airways/America West in 2007, resulted in inconvenience to passengers for weeks afterward. Baggage could be lost, flights might be missed — the list goes on.

As one high ranking United executive told Portfolio, “Officially, I have no reason to think we’ll have any problems,” one high-ranking United Airlines executive told me last week. “I really believe we have it under control. Unofficially? I’m glad I don’t have to be on a plane on Saturday or Sunday. Why risk it?”

What do you do if you’re flying this weekend? I’m going to take the below advice, and you should, too.

You could reschedule your trip, but that might be tough only a few days away from flying, and might be taking things too far. Instead, says Portfolio, have a back-up plan and know which other carriers will be going where you need to go. Make sure you print out everything relative to your trip beforehand — confirmations, ticket numbers and most important, the record locator. Get to the airport early and don’t check your bags.

Fingers crossed — If I end up on an Odyssean journey home on Sunday due to this switch, you better believe you’ll hear about it.

How to Survive United Airlines’ Big Computer Switch [Portfolio.com]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.