Juliet's soliloquy in Act III, Scene 2 of Shakespeare's Romeo and Juliet is all about her strong desire for nightfall, which is when she expects to see Romeo. In Greek mythology the sun was a flaming chariot driven across the the sky by the sun god Phoebus Apollo. He started his daily journey in the east and drove all the way across the sky to descend in the west, at which time night would begin to fall. (The sun god is depicted in one of the episodes in Walt Disney's beautiful animated film Fantasia, probably in the one which was based on Beethoven's 6th Symphony, the "Pastoral" Symphony.)
That Juliet is wishing for night to come speedily is expressed more directly in lines 10 and 11:
Come civil night,
Thou sober-suited matron all in black.
There is a contrast between the allusion to the blazing sun and the dark night, which Juliet compares metaphorically to a woman all dressed in formal black attire. By the term "civil night" she means a time that is suited to "civilized" pleasures such as wining, dining, dancing, cultural events, love-making, and sleep.
Later in the soliloquy Juliet is even more specific about her meaning where she says:
Come, loving, black-browed night,
Give me my Romeo.
So the young lady is, to say the least, impatient. She is wishing that Phoebus Apollo would whip his fiery horses and make them move much faster in order to bring nightfall sooner.