1995 (?) Mondaine Official Swiss Railroad Watch
In 1986 Mondaine introduced their wristwatch version of the Swiss Railroad Clock famous for the simplicity of its design and easy legibility. Modaine introduced a solar version of the watch, model 94177, later. The date is an estimate.
The simple, uncluttered design of the face of the Swiss Railroad watch made it very appropriate to develop into a solar version since it needed a large exposed solar cell.
In 1995 Movado made a similar introduction. They made a solar version of their well known Museum Watch.