While the Rolex GMT-Master is often credited with the dual-time complication, the Glycine Airman was actually the first purpose-built watch capable of tracking two 24-hour time zones, debuting in 1953, a full year before its Rolex counterpart. Designed in direct response to the requirements of actual pilots, it featured a unique 24-hour dial and a patented locking bezel system. By the 1960s, the Airman became the unofficial watch of the Vietnam War, favored by U.S. Air Force pilots who purchased them at military PX (Post Exchange) stores for their ruggedness and 24-hour military time layout.  

The "Special" designation on this dial marks a quirky piece of history. To bypass steep U.S. import taxes on high-jewel movements, Glycine produced this 17-jewel version specifically for the American market. This specific "Block-Text" model represents the final evolution of the classic 36mm silhouette before the brand transitioned to the high-beat SST designs in the early 1970s.