Bankrupt retailer American Apparel has proposed tweaking the timeline for its sale but said a four-week extension urged by its unsecured creditors would imperil a bid by Canadian clothing manufacturer Gildan Activewear. American Apparel said in court papers filed on Thursday that it would postpone the deadline for bids to Jan. 3 from the original proposed deadline of Dec. 19 and proposed holding an auction on Jan. 5 rather than Dec. 21.