#half-moon  the time at which the moon is at first or last quarter when half its face is illuminated
  supertype:  phase_of_the_moon  a time when the moon presents a particular recurring appearance
  part of:  month
  subtype:  first_quarter  the first fourth of the moon's period of revolution around the Earth
  subtype:  last_quarter  the last fourth of the moon's period of revolution around the Earth

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