A few weeks ago now i had this stunning IWC Pilots watch in for service featuring the 37526 movement calibre ( ETA 298X Base ), this is a unique piece and one worth mentioning here in a little detail. Although the main bulk of the movement is ETA based, the upper 24 hour/Date section is one developed by IWC for this specific model. Creating your own addition to an established movement is no small thing but in this case it works well and has since been improved.
As we already know a watch tells the time through a motion of gears that have specific ratios, it is these ratios which determine the path of the hands in order to show us the correct time. The rotation of the hour hand is once in 12 hours whilst the minute hand rotates 12 times in the same period. With the 37526 the addition of a 24 hour indication requires the clever use of additional gears in order to display a second time zone. This system is far better explained by the following link ( www.gregsteer.net ) but i add the images for those who want to view the parts were talking about >
This system has since been updated to require the use of less parts and remove an issue present with the older sprung 24 wheel. The new design is far less prone to wear and so likely keep the watch running its best for longer.
Below are some further photos of the movement during disassembly
This watch certainly appeals to those who may travel frequently and want to keep track of time on more than one continent, the technical details are also quite interesting so that link above is worth a good read. The watch service went without issue and timing had been brought back to the green so it has since been returned to its owner for some more travelling. An interesting piece i thought id share :)