The Trade Policy and Trade Review Period dictate when a trade will be completed. If the Trade Policy is "Process Immediately", the trade will be processed within the next hour. Otherwise, it will be processed following the Trade Review Period duration plus up to one hour.
It is important to note that regardless of the system, a trade will not be processed until all of the players involved in the trade are not locked. For example, if a trade is set to complete on Sunday at 2:00 PM ET but one of the players involved is locked, the trade will not process until the league rolls to following week.
Last Updated: 9/27/2011