What lines in Shakespeare's Romeo and Juliet suggest what day of the week it is?

Paris tells Lord Capulet that it is Monday on the day that he arranges Juliet’s marriage.

The events of the play take place very quickly.  The entire play actually only takes place over the course of a few days, sadly.  Romeo and Juliet meet, marry, consummate the marriage, and die within a few days.  When the play opens, Juliet is going to be fourteen in a “fortnight and odd days” (a little over two weeks)...

Paris tells Lord Capulet that it is Monday on the day that he arranges Juliet’s marriage.

The events of the play take place very quickly.  The entire play actually only takes place over the course of a few days, sadly.  Romeo and Juliet meet, marry, consummate the marriage, and die within a few days.  When the play opens, Juliet is going to be fourteen in a “fortnight and odd days” (a little over two weeks) (Act 1, Scene 3).  She doesn’t make it to that birthday. 

The day that Capulet talks to Paris is Monday. 

And bid her, mark you me, on Wednesday next--
But, soft! what day is this?

PARIS

Monday, my lord,

CAPULET

Monday! ha, ha! Well, Wednesday is too soon,
O' Thursday let it be: o' Thursday, tell her,
She shall be married to this noble earl. (Act 3, Scene 4) 

Juliet does agree to marry Paris on Wednesday, although she does not want to, but instead she is buried on that day.  She arranges with Friar Laurence to fake her death and takes a special potion.  Her parents had no idea that she was actually wed the day before to Romeo.  They thought she was available when they forced her to marry Paris.

A lot happens very quickly.  Romeo and Juliet were secretly married, Romeo killed Tybalt, Romeo was banished, Romeo and Juliet consummated the marriage, and Lord Capulet arranged Juliet’s marriage to Paris.  That is where you get the makings of a tragedy.  Haste makes waste.