Tomorrow's scheduled start of the hockey season was delayed today by the National Hockey League. Despite an offer extended by players yesterday not to strike and to play without a collective-bargaining agreement, N.H.L. commissioner Gary Bettman decided a contract was necessary. Both sides will return to the negotiating table, but players will not take to the ice in the interim. If a deal is struck in the next two weeks, officials say that regular season games can be made up.