Deadline on US-Taiwan Arms Deal
Also included in the arms package that Taiwan's KMT has prevented from passing are 8 diesel submarines, which are also vital to Taiwan's defense. A good history of Taiwan's submarine fleet and attempts to expand and modernize it can be found here.
More important than the arms themselves is the message that Taiwan is sending to the United States as to its willingness to prepare itself for a possible conflict and its commitment to defend itself should the need arise. America's "Vietnam Syndrome" causes it to constantly examine each country it promises to defend for signs that the country is not willing to defend itself. If this arms deal doesn't go through, America may find itself questioning its defense commitment to Taiwan.
More than thirty members of Congress have already expressed to Lien Chan their opinion on the matter.
Update: This article however, claims there is no such deadline.