Date change at midnight (ish)

[Mr Ben]

Sorry for the stupid question but interested to know the answer to this one. I’m sure it’s been asked and discussed before but I’m not getting much of use out of the search function.

Other automatic watches I’ve had in the past show the date changing very gradually around midnight. Eg an old Tag I have, it’s evident the date wheel is moving from about 23.50 then it clicks through the last of the actual change at 00.02.

My current model (Explorer II 226570 so 3285 movement) doesn’t move at all until about 00.06 then changes very suddenly.

Is this something thats generally accepted and what causes it? eg a slight misalignment or design of the movement and how far out would be expected? I’ve had the watch a month and it’s only about 2 seconds off my iPhone over 30 days from initially setting it so surprised the date change is so much less precise. (Not that I desperately need to know the date in those 6 minutes but just interested!)

[Dirt]

It is my understanding that your Rolex is within the acceptable tolerance range for the change according to Rolex. It could be altered very easily by re-seting the position of the hands. To that, it will probably be different whenever it comes back from a service.
The Rolex has a quickset mechanism and that's the reason it flips instantly and also the reason why one can change the date at any time of the day without damaging the movement. There's no need to be concerned about changing the date during the critical time period on a modern Rolex because of the quickset mechanism.

I can't speak to the TAG but some change progressively over a number of hours. Hense we need to be mindful of the critical range.

[Tools]

Originally Posted by Mr Ben

. . .

Other automatic watches I’ve had in the past show the date changing very gradually around midnight. Eg an old Tag I have, it’s evident the date wheel is moving from about 23.50 then it clicks through the last of the actual change at 00.02.

My current model (Explorer II 226570 so 3285 movement) doesn’t move at all until about 00.06 then changes very suddenly.

Is this something thats generally accepted and what causes it? eg a slight misalignment or design of the movement and how far out would be expected? .
. .

"Other" watches engage gears and slowly turn the wheel to another day. For some this takes several hours.

Rolex uses a cam and flat spring. When the cam reaches midnight, the spring is released and snaps the wheel to the next day instantly, as your Explorer is doing.

The mechanism works with each 24 hour turn of the entire movement. The hands you see are a visual representation of time but are not physically attached to the date wheel. When a movement is assembled, the hands are the last thing put on and will be a few minutes either side of when the cam slaps the date spring.

[Mr Ben]

Thanks - that’s a helpful summary and pointers. I’m sure I can find some diagrams, videos etc to learn a bit more as well - I had looked at my watch on Year’s Eve and noticed the date hadn’t changed just after midnight and then when I looked back a few minutes later, it had changed and I wondered when it did.

I happened to go to bed at midnight last night so made a point of watching it and was surprised how how different it was to other watches I own.

[WatchMySix]

Originally Posted by Mr Ben

Sorry for the stupid question but interested to know the answer to this one. I’m sure it’s been asked and discussed before but I’m not getting much of use out of the search function.

Other automatic watches I’ve had in the past show the date changing very gradually around midnight. Eg an old Tag I have, it’s evident the date wheel is moving from about 23.50 then it clicks through the last of the actual change at 00.02.

My current model (Explorer II 226570 so 3285 movement) doesn’t move at all until about 00.06 then changes very suddenly.

Is this something thats generally accepted and what causes it? eg a slight misalignment or design of the movement and how far out would be expected? I’ve had the watch a month and it’s only about 2 seconds off my iPhone over 30 days from initially setting it so surprised the date change is so much less precise. (Not that I desperately need to know the date in those 6 minutes but just interested!)

That's funny because my date changes over at 0006 as well.


Sent from my iPhone using Tapatalk

[padi56]

Don't worry when the date changes it can be a few minutes different either way. Dont forget its purely a mechanical process its not like switching a electronic switch. Rolex uses a cam system date change and sometimes they can get a bit dry from constant daily use, so it could take and extra minute or so for the jewel to slide off the cam, it does not indicate a problem with the watch.The most important thing that it changes by morning when you wake up,and you can see its changed, now thats far more important. As it proves you are still alive to live another day, hopefully in years to come to enjoy wearing your Rolex for many future decades .

[Alexjb007]

La tolerancia de salto en la programación está entre -1 minuto a + 1 minuto, no perjudicando en el funcionamiento cualquier salto fuera de la tolerancia.

[Annan]

All normal. Between my wife and I we have owned about 12+ Rolexes over the years. Only one, a DJ31 changed exactly at midnight.

[Jessiecopeland]

Originally Posted by Mr Ben

Sorry for the stupid question but interested to know the answer to this one. I’m sure it’s been asked and discussed before but I’m not getting much of use out of the search function.

Other automatic watches I’ve had in the past show the date changing very gradually around midnight. Eg an old Tag I have, it’s evident the date wheel is moving from about 23.50 then it clicks through the last of the actual change at 00.02.



My current model (Explorer II 226570 so 3285 movement) doesn’t move at all until about 00.06 then changes very suddenly.

Is this something thats generally accepted and what causes it? eg a slight misalignment or design of the movement and how far out would be expected? I’ve had the watch a month and it’s only about 2 seconds off my iPhone over 30 days from initially setting it so surprised the date change is so much less precise. (Not that I desperately need to know the date in those 6 minutes but just interested!)

It’s called instantaneous date change.
They have designed this mechanism to be as precise as possible. It should happen exactly the same each day, with in seconds of the previous day.
Keep in mind this is a purely mechanical mechanism where inaccuracies could and should be expected.


I am a little confused. Were you worried that it happened 6 seconds after midnight?
That’s very precise in the mechanical world.

Expecting it to change each day according to you iPhone is a little out of range for many reasons.
Your watch is either gaining or losing at least 2 seconds daily minimum.
Your iPhone, should be exact. Every day.
If you took a reading on Monday and it was 6 seconds slow, by next Monday it could be much slower or much quicker, according to you iPhone.

[Vince_76]

Mine does the same. No worries - it’s normal

[Redemption144]

Originally Posted by WatchMySix

That's funny because my date changes over at 0006 as well.


Sent from my iPhone using Tapatalk

Just to clarify - you guys are saying that the date changes suddenly 6 minutes after midnight right? Not 6 seconds after midnight.

[swissfrank]

My date just 3230 movement date change was usually 6 or 7 minutes past 12:00.

[swissfrank]

My datejust changed the date instantly 6 or 7 minutes
after 12:00 with a little click sound.

[brandrea]

Originally Posted by Tools

"Other" watches engage gears and slowly turn the wheel to another day. For some this takes several hours.

Rolex uses a cam and flat spring. When the cam reaches midnight, the spring is released and snaps the wheel to the next day instantly, as your Explorer is doing.

The mechanism works with each 24 hour turn of the entire movement. The hands you see are a visual representation of time but are not physically attached to the date wheel. When a movement is assembled, the hands are the last thing put on and will be a few minutes either side of when the cam slaps the date spring.

Nice summary Larry. I don’t think I’ve ever heard it explained this way

[jatco]

Originally Posted by brandrea

Nice summary Larry. I don’t think I’ve ever heard it explained this way

Been watching a lot of Youtubes of qualified people doing restorations and services to many watches and that is the mechanics behind the date wheel and its relation to changing/flipping over. Quite the interesting mechanics of it all...

[Alexjb007]

Precision
https://youtu.be/-q11QakS6KE

[Alexjb007]

Un clásico
https://youtu.be/qogCoOIDM7A

[Alexjb007]

Explorer
https://youtu.be/4TKbnQhIlUM

[jatco]

The most accurate was 1st one on the precision..
but all 3 are not cased..which could make a difference...
Cool tho.......

[Kensk]

Originally Posted by Tools

"Other" watches engage gears and slowly turn the wheel to another day. For some this takes several hours.

Rolex uses a cam and flat spring. When the cam reaches midnight, the spring is released and snaps the wheel to the next day instantly, as your Explorer is doing.

The mechanism works with each 24 hour turn of the entire movement. The hands you see are a visual representation of time but are not physically attached to the date wheel. When a movement is assembled, the hands are the last thing put on and will be a few minutes either side of when the cam slaps the date spring.

Is this the same for Tudor watches? My Peli changes at around 12:25, dont really bother me but would it be worth getting it looked at?

[Renbro]

great to read through :) thanks

[Flipmarine2k]

My 1982 day date changes 1 minute early. My 2022 Datejust changes 4 minutes past midnight

[jbwm2311]

Yep. My 2022 DSSD slaps onto the next day at exactly 00:04:55 every time. Usually though I'm either too asleep, too busy drinking, or too busy not looking to notice!

[tifosi]

I can hear my date change at 5 minutes past midnight. If I'm still awake.

[Mr Ben]

Originally Posted by Jessiecopeland

It’s called instantaneous date change.
They have designed this mechanism to be as precise as possible. It should happen exactly the same each day, with in seconds of the previous day.
Keep in mind this is a purely mechanical mechanism where inaccuracies could and should be expected.


I am a little confused. Were you worried that it happened 6 seconds after midnight?
That’s very precise in the mechanical world.

Expecting it to change each day according to you iPhone is a little out of range for many reasons.
Your watch is either gaining or losing at least 2 seconds daily minimum.
Your iPhone, should be exact. Every day.
If you took a reading on Monday and it was 6 seconds slow, by next Monday it could be much slower or much quicker, according to you iPhone.

Didn’t realise this thread was still getting replies. I think the question’s been answered above but it wasn’t 6 seconds - I had wondered why the watch was exactly 6 minutes “late” changing every night. Six minutes past midnight on the dot every night.
Thank you all for the replies.

[007Sub]

Originally Posted by Mr Ben

Didn’t realise this thread was still getting replies. I think the question’s been answered above but it wasn’t 6 seconds - I had wondered why the watch was exactly 6 minutes “late” changing every night. Six minutes past midnight on the dot every night.
Thank you all for the replies.

Date change alignment has to do with how accurate the watchmaker chose to be (or was able to be) on the day he or she mounted the hands. It has nothing about the movement quality. Getting the hands to align exactly at midnight at date change is absolutely possible (given an instantaneous date change system), however, easier to do on some calibers than others. Anything outside of +/- 2mins of midnight is just laziness or ineptitude on the part of the watchmaker that set the hands.

[chiumeister]

Why is it that when I manually wind the minutes hand, the date changes at midnight. But when it runs mechanically, the date changes minutes after midnight?

Is there a way without having the Rolex watchmaker open my GMT II, for me to adjust by (hand)?

[ganagati]

I’ve read it’s a function of where the watchmaker sets it. It’s an alignment thing. They attempt to get it right at midnight, but as long as it’s close it passes quality.

[Andad]

Originally Posted by ganagati

I’ve read it’s a function of where the watchmaker sets it. It’s an alignment thing. They attempt to get it right at midnight, but as long as it’s close it passes quality.

RTT.

[chiumeister]

Originally Posted by ganagati

I’ve read it’s a function of where the watchmaker sets it. It’s an alignment thing. They attempt to get it right at midnight, but as long as it’s close it passes quality.

I guess under 10 minutes is close enough.