How do Romeo's banishment and the change in Juliet's wedding date affect the central conflict of the play?

Because Juliet's wedding day is moved up by one day by her father, the Friar's messenger does not have time to get to Mantua (the city where Romeo has gone because he was banished from Verona) to tell Romeo of his plan. So when Romeo hears from His servant that Juliet is dead, he does not know she is just under the influence of a heavy sleeping potion--she is not really dead. He races back to Verona and kills himself before the potion has time to wear off.