Portal:Anniversaries/June 3
- 1965 — American astronauts James A. McDivitt and Edward H. White wear Omega Speedmaster watches while orbiting the earth 62 times in 4 days aboard the Gemini IV spacecraft
- 1971 — American company Zenith Radio Corporation acquires Movado-Zenith-Mondia, holding company for the unrelated Zenith watch company.
- 2020 — H. Moser & Cie. and MB&F introduce the Endeavour Cylindrical Tourbillon H. Moser x MB&F and LM101 MB&F x H. Moser, the former of which would win the Audacity Prize at the GPHG that year.