Recently acquired this two tone blue beauty which I assume utilizes cal 431. Based on my past experience with Ultra Chrons the manual date adjustment was performed by cycling between 9 pm - 1 am. However I’m unable to do so on this model despite no issues with the date advancing at midnight. Was there a point in the Ultra Chron’s production where the date was not adjustable? Or does watch just need a repair?

 

I dunno but I like it. Is that also the original bracelet?

 

I believe so. It’s a Longines signed JB Champion bracelet.

 

With some watches that are not equipped with a quick change calendar, watch for this! After the date changes ahead one day when setting the hands ahead, does the date numeral back up when you turn the hands backwards past midnight? If it does, you’re likely sunk. If it doesn’t back up when you turn the hands backwards, try turning the hands back to 6:00 pm, then back to midnight. Chances are that will help setting the calendar more easily.

 

But on the bright side, at least you can go backwards if that gets you to the correct date faster.

 

Thanks for the tip. The date numeral doesn't back up when turning hands backwards past midnight. However, turning hands back to 6 pm then to midnight did not advance the date. Looks like it may need a service.

 

Either that or a new owner. I'll gladly send ya $200 as I never bother with the date function anyways.

 

Sure...send the $200 first