What the other guys said is correct. to expand. If it ends in an odd number it only has a date wheel. If it ends in an even number it is the same movement but with a day and a date wheel.Between the 7s25, 7s26, and the 7s35. I have 2 7s26's in the 007's and had a 7s35 in the White Sammy. I believe the 7s35 had 23 jewels? But now I see reference to the 7s25 in the Ti Sammy's. Are the 23 jewel movements any better than the 7s26?