Mercury stations retrograde on May 29, 2021 at 24° Gemini, and direct on June 22 at 16° Gemini — 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.