Originally introduced in 1956, the Day-Date was the first wristwatch to display the day of the week and date in fully written words. This distinctive feature remains one of the most distinctive features of Day-Date watches to this day. This was a significant innovation in the watch industry and contributed to the enormous popularity of the Day-Date.

The 18238 was the first Day-Date with the caliber 3155. This new movement was much better than the old caliber 3055. What made the 3155 different was that it could quickly change both the date and the day, while the 3055 could only do the date quickly. Besides the improved movement, the ref. 18238 is a perfect example of a Day-Date watch. It has a classic dial, a solid gold 36mm case, and a fancy grooved bezel. All of this makes it a very elegant and versatile watch.