Perpetual Calendar - Discovery Series, Caliber 6M13, 1991

The Discovery Series
was commemorating the 500th year of the landing of Christopher Columbus in the New World in 1492. The case back of this series always depicted the famous ship of Columbus.

Search Weekday Function
from 1400 to 2499 you can look up any weekday! The switch from the Julian (introduced 45 BC by Roman emperor Julius Caesar) to the Gregorian (Pope) calendar took place in 1582. October 15th followed October 4th by papal bull, thus 10 days were dropped. The chip does not do this calculation, so one has to remember that date and that 10 days needed to be dropped when checking for weekdays of dates before October 15th 1582.
All functions are very easy to use, despite the many hands and buttons. A very intuitive and great user interface. Compliments to the gentlemen from SEIKO who designed the 6M13. Very nice. I had not been wearing the watch for a very long time, yet, I could immediately play with all functions and I had no manual at hand.
Maybe the only thing (of course to save battery life!) is that the date in the date window changes really slow, so you need a bit of patience to look up the weekday of a given date or also to set the One Day Alarm. Besides that all is great in my opinion, I really like this caliber 6M13.