Beginning from the central axis, we see the hours and the minutes, as well as a GMT hand. Just below the axis is a linear scale that shows the difference between solar time (how time would be measured by a sundial) and mean solar time (how we show time on watches and clocks), according to the equation of time. Along the flange, in the lower right-hand portion of the dial, an arrow points to the hour that the sun sets at the watch owner's pre-programmed home location. On the left, a similar scale tells the hour of sunrise at home. A sub-dial at three o'clock is marked with the letters D (for December), S (for September), J (for June) and a date window where there could have been an M for march. This calendar function is linked to the equation of time. But let's go back to that date window, this seemingly unassuming complication actually comes with a patented innovation of its own. The polarized crystal date consists of transparent borosilicate glass, making all parts of it effectively invisible to the naked eye, with the exception of the specific date that happens to be beneath the the polarized glass date window. This allows an unfettered view of the skeletonize movement and its functions.