The husband and I called from Las Vegas last week at 1 p.m. local time - so 4 p.m. EST - and got the Air Tran Elite line message that they're open 7 a-7 p. Again, this was at 4 p.m. EST, so, go figure.
We were calling to use points to upgrade to biz class, so we called the regular Air Tran line, waited for a bit with the rest of the non-Elites, and had our request taken care of without any problems by an Air Tran agent.
Interestingly, even though we are both Elites and were on the same itinerary, he had already been upgraded to biz class, yet I had not (this was not a Y fare) - and there were eight empty seats. The agent had no idea or explanation as to why, but I wanted to burn some points, anyway, since I'm never flying WN, so it was no big deal to use my four points - just odd.