I think the symbolism represented by the beautiful, luminous moon is a good example. Hardy uses it to represent love. The phases of the moon and even if it is present or not say a great deal about romantic love and if it exists between the characters or not. How each character feels about love is associated the the nightly wonder in the heavens.
Gabriel is accustomed to stare gazing to tell the time but then he sees Bathsheba on a night when no moon is out. After she rejects his marriage proposal the moon is said to be in a waning period. Another reference to the moon was when Bathsheba failed to show emotions for Bolwood, yet he was infatuated with her. A situation of unequal love that drives Bolwood crazy.