The 5205G-013 is a fantastic modern annual calendar from Patek Philippe, and is full of features. As opposed to some other models in the range, most of the information is all housed in apertures at the top of the dial which keeps the dial clean and easy to read. There is a moon phase sub dial at the 6 o clock position and around that subdial is a 24-hour indicator. The hours are displayed by large batons. The dial is the main change with the white gold releases, now in a single colour this is the blue version. The 40mm case is beautifully sculpted and has carefully pierced lugs. Due to the fact that the watch makes use of the 324 S QA LU 24H movement it only needs to be adjusted once a year,on March 1st, and the moon phase is so accurate that it only deviates from the lunar cycle one day every 122 years.