Mercury stations retrograde on May 5, 1917 at 29° Taurus, and direct on May 29 at 20° Taurus — 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.