Question for our elders or more well informed

[worktolivelife]

here goes, on previous Quartz watches if i changed the date PM the date did not flip over at midnight. now is this the same with a mechanical movement I know I could just try it and find out, but really after a bit of an insight into the mechanicals. My assumption is that the watch engages the date mechanism after it has gone round 24hrs so it is the revoloutions of the hour/minute hands that determine when the date changes, in effect having a inbuilt AM/PM sense ???


steve

[worktolivelife]

so even changing the date in the early evening it would still changeover at midnight, if the hands were in the right am/pm phase

Thanks Gents

steve

[padi56]

Most mechanical calendar or date watches are not AM/PM aware,they simply advance the date every other time the hands pass forward across 12:00. Where people get confused with this is because they assume it is more complicated than that, but its as simple as that.When setting a watch that has stopped run down, make sure you roll the hands forward past 12:00 at least once before setting the time so you can see when the date changes. Then set the time accordingly so the next date change will occur at midnight,and not at 12 noon.They recommend to never change the date between 8-10pm-2am. Because the pinions are repositioning themselves to carry out the automatic date change, and any interference at this moment could damage the movement.

[worktolivelife]

I knew you were out there mate!

so if the mechanicals change the date every other pass of 12 by the hands and only engage the date on the 2nd pass by resetting the date in the afternoon this does not re-set anything then??? . so the date will change again at midnight regardless of if you have physically changed it yourself, only just earlier in the evening.

steve

[worktolivelife]

sorry if I'm not making myself clear Padi, as a for instance date change in a short calender month, do you Need to do the date AM will changing it in the afternoon throw out the next date change as I mentioned with a previous quartz it seemed to reset everything when the date was set, time of reset being AM regardless

thanks

steve

[Rockrolex]

Originally Posted by worktolivelife

sorry if I'm not making myself clear Padi, as a for instance date change in a short calender month, do you Need to do the date AM will changing it in the afternoon throw out the next date change as I mentioned with a previous quartz it seemed to reset everything when the date was set, time of reset being AM regardless

thanks

steve

Not quite sure what you're getting at, Steve. Are you talking about a quartz with a mechanical movement (i.e. analog dial)? Digital quartz watches change exactly at 12:00:01 AM because they're all electronic, so it's just a bunch of digital signals.

Mechanical movements don't know from AM or PM. You determine that when you set the watch. Think of it this way: The date changing mechanism operates once every two rotations of the hour hand mechanism. When you set the watch, you have to set it based on whether the real (external) time is AM or PM if you want the date to change correctly. When setting the watch, the first 12 hour rotation after the date changes will be AM; the second 12 hour rotation will be PM. So if you are setting the watch in the morning, you set the correct time as part of the first 12 hour rotation. Likewise, if you are setting the watch in the afternoon, you go through the first 12 hour rotation and set the correct time as part of the second 12 hour rotation.

As Peter said, most manufacturers do not recommend changing the date between the 8PM - 2AM time window (on the watch) because it could affect the functioning of the gears and pinions. The GMT-II is one of the few exceptions to this rule.

[worktolivelife]

so manually changing the date in the afternoon would reset the working if you like? it would now take 2 turns of the dial for the date to changeover again, or is there no such "reset" connecting the hands and the date feature and the 2 remain separate the gears on the hands engaging the date only after 2 turns whatever time of day you manually change the date

steve

[Rockrolex]

Originally Posted by worktolivelife

so manually changing the date in the afternoon would reset the working if you like? it would now take 2 turns of the dial for the date to changeover again, or is there no such "reset" connecting the hands and the date feature and the 2 remain separate the gears on the hands engaging the date only after 2 turns whatever time of day you manually change the date

steve

When you say manually change the date in the PM, are you talking about a quick set date change, like on the DD or DJ? If so, changing the date in the afternoon will not affect when it changes with the hands. It's the time setting that controls the date change. If the time setting is in the 2nd 12 hour rotation, the date will change with the next 12 hour rotation. It doesn't matter what the date reads in the dial.

[worktolivelife]

Thats it ED!!!! 3135 movement, realife scenario, my watch is now reading the correct pm time date in sync!, but its the wrong date so I'm just gonna change it now pm , and it will change as normal again later tonight as usual


thanks

steve

[Rockrolex]

Originally Posted by worktolivelife

Thats it ED!!!! 3135 movement, realife scenario, my watch is now reading the correct pm time date in sync!, but its the wrong date so I'm just gonna change it now pm , and it will change as normal again later tonight as usual


thanks

steve

You got it, Steve. Good luck.

[RobDad]

I was confused, but looks like you nailed it!

I always change date in the morning, just as a matter of habit - but it seems to be the most sensible way to go 'mechanically' so as not to screw up the datechange mechanism

[JJ Irani]

Hey Steve,

Still not sure what you're trying to ask, but this is what I could infer.

Say, for example, today is the 30th of April. Tomorrow is the 1st of May, so naturally you have to skip '31'.

Right!! So all you do is this...on the night of the 30th April (but make sure you do this before 8 pm), unscrew the crown to position '2' and flick the date over to '31'. Then you can go to bed rest assured that when you wake up the next morning, the date will be showing '1'.

Cheers - JJ