If Garth is smart, he starts lowering his demands around noon...
until then, he has the best chip out there and other teams know it. However, if nobody meets his price by then, he risks teams panicking and going elsewhere. He has to complete the deal before teams panic. As long as there are 3 hours left, teams should feel pretty comfortable they won't get left out in the cold. However, as time starts growing short, teams will feel compelled to get something done even if it isn't for the best player available.