Mercury stations retrograde on August 7, 1991 at 5° Virgo, and direct on August 31 at 23° Leo — 24 days. From the Earth, Mercury seems to back up against the stars as we overtake it, as a car passed on the highway seems to slide backward. Astrology holds it a time for crossed wires and delays. Computed from JPL's approximate orbits; the stations agree with an almanac's to within minutes.