Months ending in less than 31 days

[flmprsrv]

A question for those knowledgeable in the care and feeding of a Rolex cyclops sub.

For months fewer than 31 days, what is the best procedure to move the date forward? It is now afternoon where I am. If I were to advance the date to 31, would the movement know that it was PM, and advance to the 1st at midnight?

Is one better off waiting until the morning of the 1st to advance?

Thanks in advance for the info.

[Rscmaine]

Actually, to avoid wear and tear I hack mine on the 28th, then re start it 28 days later.

(I think you can advance the date at any time - your watch knows whether it is am or pm via a little cog which only turns once every 24 hours.)

[CPTL]

Great question. Yeah, the movement is designed to advance the date wheel once every 24 hours. The date wheel is linked with the hour hand, so advancing the hour hand advances the date gizmo, until it snaps forward right at midnight (plus or minus a minute or so).

So...advancing the date wheel does not affect when your watch flips the date. If you set it to 31 right now, it will be on 1 in the morning.

Simply pull the crown out to the date-advance position.
1. When you unscrew the crown, it pops out to the winding position. The second hand continues to tick, and twisting the crown winds the watch.
2. With a slight tug, crown will be in the date-advance position. The seconds are still ticking. Turning the crown in this position will advance the date.
3. With a firmer tug, the crown will be in the time-setting position. Movement is "hacked" (seconds stop ticking).

[flmprsrv]

Thanks for the replies. What a superb forum!

[Rscmaine]

Of course, my first suggestion works just as well if you're not in any hurry...