I've done a lot of reading (and made calls) since I'll be arriving May 7th. Numerous sources say weekdays are best for less crowds - that while a lot of kids are still in school, Saturday and Sunday are still very busy with locals. Of your choices, I've been told Friday is best, then Sunday, then Saturday last.
Orlando was 2003 last for me, but I live in San Diego and visit our SeaWorld a lot, including having the annual pass. If you're traveling with young kids, or a senior, and really want to enjoy the park and see most or all of it, I'd be surprised if you can see everything in one day without rushing or looking at your watch all day. (And this is one Type-A to another.)
If you go early and stay late, don't mind feeling rushed sometimes, don't need to see it all, okay on the kid front (none, or not easily exhausted), won't arrive 30 minutes early for every show, won't do all the rides so not much time standing in line (like for the coaster), then yes, one day may do it. There are quite a number of shows, and the problem is they're all really good, so it can be hard to decide which ones not to see. Then, throw in the shark exhibit... some people I know rush right through (once you get inside), but others (including me) stay in there for quite a while so it can be a time waster. For Shamu, definitely arrive way early for that show.
Anyway, bottom line, to really enjoy the park, I'd suggest rethinking doing it in one day, or shoot for one day but have a backup day if you find you need a second day. Friday would be my suggestion based on what I've been told, especially given that one of our weeks will overlap so we're actually looking at the same time frame.
Good luck, and hope you have a blast!