In Act 4 Scene 2, after Juliet agrees to marry Paris, what change does Capulet make in the wedding plans?
It's an unexpected twist in the play. Juliet thought she had a whole day (i.e. Wednesday) to get ready for the wedding (today is Tuesday, and the wedding is set for Thursday). But Capulet gives everyone a bit of a shock:
Send for the County. Go tell him of this.
I'll have this knot knit up to-morrow morning.
Nurse, will you go with me into my closet
To help me sort such needful ornaments
As you think fit to furnish me to-morrow?
No, not till Thursday. There is time enough.
Go, nurse, go with her. We'll to church to-morrow.
He insists the wedding is brought forward a day: Juliet and Paris are to be married TOMORROW (Wednesday). This has a pressure-cooker effect on this part of the play. Juliet has to take the potion that night: there's no time to think things over or try to get a message to Romeo herself. She has to trust the Friar.
Hope it helps!