Stupid Date Change Question

[Brew]

I am sorry for this one, but if I was able to stay up with the grown ups, I might be able to research the answer to this one on my own.

Does the time at which the date changes differ if forced to change via setting using the crown vs. just flipping over in the ordinary course of showing the time/date?

Thanks in advice for helping solve one of life's little mysteries.

[brandrea]

I believe they are the same Larry. Now you’ve got me wondering if I’ll have to stay up late to find out

[padi56]

Originally Posted by Brew

I am sorry for this one, but if I was able to stay up with the grown ups, I might be able to research the answer to this one on my own.

Does the time at which the date changes differ if forced to change via setting using the crown vs. just flipping over in the ordinary course of showing the time/date?

Thanks in advice for helping solve one of life's little mysteries.

No the date can only change if not using the crown when the hour hand has made two complete clockwise revolutions around the dial.

[Abmatt2002]

You could set the watch to change the date at midday, if that’s what you mean.

[Brew]

Originally Posted by padi56

No the date can only change if not using the crown when the hour hand has made two complete clockwise revolutions around the dial.

I have to be honest: this has sent my little brain to spin around its axis way too early over here.

[Andad]

Originally Posted by Brew

I am sorry for this one, but if I was able to stay up with the grown ups, I might be able to research the answer to this one on my own.

Does the time at which the date changes differ if forced to change via setting using the crown vs. just flipping over in the ordinary course of showing the time/date?

Thanks in advice for helping solve one of life's little mysteries.

Yes Larry, I think it does.
The only way to know when it changes is to watch the date change via the movement.
If you try to check the change point using the crown I think it is slightly different.
Or just check it the next day as I do,

[j0hnny]

I think what he means is he wants to know at what precise time his watch changes date at midnight. Rather than stay up he's asking if he manually winds the watch hands around this will show him exactly when it changes. I think this is what he means!! My watch changes over at about 3 mins past midnight, might manually wind it and see?


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[Andad]

Originally Posted by Abmatt2002

You could set the watch to change the date at midday, if that’s what you mean.

Good idea, you can check it while you have lunch.

[GreatScott]

Just set a false time and watch it...geez.

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[j0hnny]

During the normal course of my watch keeping time and moving through the date change at midnight it flips over at 3 minutes past midnight. If I manually wind it through to the date change it flips exactly at midnight.


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[j0hnny]

Originally Posted by GreatScott

Just set a false time and watch it...geez.

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Good idea!


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[Tools]

Originally Posted by Brew

. . .
Does the time at which the date changes differ if forced to change via setting using the crown vs. just flipping over in the ordinary course of showing the time/date?

Thanks in advice for helping solve one of life's little mysteries.

Yes, it will be slightly different.

Using the crown, you push all of the gear train slack in the opposite direction from the mainspring torque. Since a Rolex does not have gear interaction, but a cam plate, to slap the date ahead, the dial representation may be slightly different between the two when that spring is released.

[schoolboy]

Originally Posted by Brew

I am sorry for this one, but if I was able to stay up with the grown ups, I might be able to research the answer to this one on my own.

Does the time at which the date changes differ if forced to change via setting using the crown vs. just flipping over in the ordinary course of showing the time/date?

Thanks in advice for helping solve one of life's little mysteries.

That's actually a very good question. I think it does differ indeed. I called RSC Dallas about the tolerances on the date change (like changing at 12:05 instead of 12).

They explained that when a watchmaker sets the hands, they set them so that the change happens at 12, but since the watch is mechanical, when the date changes "in the ordinary course," things like lubrication, gravity, and where the gears are at can affect it a little bit.

They said that if you stay up and check the exact time the date changes, you will see that it varies from day to day too.

[schoolboy]

Originally Posted by j0hnny

During the normal course of my watch keeping time and moving through the date change at midnight it flips over at 3 minutes past midnight. If I manually wind it through to the date change it flips exactly at midnight.


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Exactlly!

That is what RSC explained would happen

[schoolboy]

Originally Posted by Tools

Yes, it will be slightly different.

Using the crown, you push all of the gear train slack in the opposite direction from the mainspring torque. Since a Rolex does not have gear interaction, but a cam plate, to slap the date ahead, the dial representation may be slightly different between the two when that spring is released.

Awesome.

Thanks for sharing Larry

[Brew]

Originally Posted by Tools

Yes, it will be slightly different.

Using the crown, you push all of the gear train slack in the opposite direction from the mainspring torque. Since a Rolex does not have gear interaction, but a cam plate, to slap the date ahead, the dial representation may be slightly different between the two when that spring is released.

This is great, thank you.

[Greg 59]

Originally Posted by padi56

No the date can only change if not using the crown when the hour hand has made two complete clockwise revolutions around the dial.

That's not what he's asking. He wants to know whether the exact time that the date changes differs if you do it manually by turning the crown as opposed to automatically by allowing the watch to do it.

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[Dirt]

Originally Posted by Tools

Yes, it will be slightly different.

Using the crown, you push all of the gear train slack in the opposite direction from the mainspring torque. Since a Rolex does not have gear interaction, but a cam plate, to slap the date ahead, the dial representation may be slightly different between the two when that spring is released.

Precisely

And there can be day to day variation of the changeover time.
Recently somebody on the forum also logged a shift in the changeover time over quite a long period.

As Padi would say, it's more important the date has changed over the next day when one is awake.

[Singslinger]

You learn something new every day!