Your suggested time is on Friday at around 5am for me I think. There's no way I'd be out of bed by then. The current time slot is on Wednesday around noon which is awkward as I have been coming in and out of my office needing to talk to me. The original setup was Saturdays at noon was the best for me and why I always tuned in then as I'm generally chilling out coding around that time.

I thought the Wednesday mid-day time was going to kill my participation dead in it's tracks, but I had a massive life-change at about the same point you changed the schedule, which meant I was free at that time of day, albeit still a little busy. I'm a late sleeper, so the crack of dawn on Friday morning would rule me out entirely unless I totally rearranged my weekly activities.

EDIT: Rebecca's suggestion above sounds good to me.