Two key e-commerce leaders--Wal-Mart and Macy's--<A HREF="http://www.eweek.com/article2/0,1895,2063540,00.asp?kc=EWNAVEMNL112706EOAD">found themselves shut out</A> of the online portion of the holiday sales rush for much of Friday, as their sites slowed to a crawl. This was especially troubling as it happened on the so-called Black Friday, where major retailers hope to see their financial ledgers go from being in the red to being in the black. This trend, however, may be changing, as online sales start to challenge brick-and-mortars for market share and as the day after Thanksgiving starts to become a much less significant day for e-commerce players. The most important date for e-commerce players may instead be late in December. One industry report placed the new date as Dec. 18.