On June 1, Jenkins Realty Inc. sent a written offer to Jones for the sale of a house. The offer included a sentence which said the acceptance must be delivered to the office of Jenkins Realty Inc. by 4 pm on June 30. At 8 am on June 30, Jones gave the letter of acceptance to a special messenger service. Due to an unexplained delay, the letter of acceptance did not reach Jenkins Realty Inc. until July 1.

Is there a contract? If so, explain please.