They will just work extra hours or something to put it together, im sure they know this because of the Tuesday and Wendsday show - its normally Tuesday, Thursday then Sunday.
If you think about it, the person who wins HOH on Thursdays has to nominate on Friday. So im sure they could just add more of the nom ceremony, or air them getting to know each other better and such. I mean really whats in between those anyways? Its the nom ceremony and the POV ceremony but I don't think its such a big deal.
Wait, I didn't make any sense did I?