The company will kick off the program that allows shoppers to pay for holiday gifts and other products in installments, on August 28, two weeks earlier than last year, Anne Marie Kehoe, vice president of toys, said in a briefing. The move reflects Wal-Mart’s desire to get a head start on a holiday season that is sure to be highly competitive. Toys are an especially big focus for retailers this year, ahead of the December release of “Star Wars: The Force Awakens” – the first in a new “Star Wars” trilogy being produced by Walt Disney Co.