Glycine Watch SA, or simply Glycine, is a Swiss watchmaker founded in 1914 in Biel/Bienne (BE), Switzerland, where its manufacturing and headquarters remain today. In 1930, Glycine released the first mass-produced automatic watches, and in 1959, it developed vacuum-sealed cases, allowing for more durable and water-resistant timepieces. The Glycine Airman, the first watch capable of tracking two 24-hour time zones, has been used extensively in commercial and military aviation, as well as in spaceflights; notable examples include its use by United States Air Force pilots during the Vietnam War and astronaut Pete Conrad during the Gemini 5 and Gemini 11 spaceflights.