SWA & TTF Extension ??

[Figment&Piglet]

I know SWA's schedule should open up tomorrow morning (6/23), but I have a TTF credit that expires on Friday 6/26. I believe I have to wait until it expires in order to pay the $50 to extend it and use the rest of it to book my November tickets, right? Will they let me extend it ON Friday, since that's the day it expires, or do I have to wait 'til Saturday? Or even worse, 'til Monday?

(I wish they'd just let me extend it now so I could book my tickets tomorrow morning! ARGH! I have NO patience! )

Thanks!