Why can't I turn back the date?

The other day I tried to adjust the date on my Port Auto from the 31st to the 1st. Somehow I ended up setting the date to the 2nd. I thought I could just turn the crown in reverse to make the date go back but then realized this is not possible. Instead I had to go forward(1-2-3-4...) which was not a huge problem but rather more of a nuisance.

Does anyone know why adjusting the date in reverse is not possible? Is there any technical/mechanical reason why my Port Auto cant do this? Or was this just a conscious decision by the watch designer?

Well..It is like time, designed to go forward >

Hi tboooe,

I do beleive there are mechanical reasons for this of which I am not sure of all of them or their depth.

However, if I may make a suggestion...why not take the time with your Port to slowly advance the date display enjoying the mechanism as you do. You will get a lot more enjoyment from your Port this way.
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Cheers from Isobars.

i'm pretty sure mine goes forward only too.

Check this post..

Look a bit down for the post from Richard Sheridan, posted on 24-11-2008 and called: "What is that Component?"

It shows the mechanism that advances the date. It contains a spring that makes the date 'jump' close to midnight instead of turn slowly. If this would be turned backwards, the forces on the spring would work in the wrong direction, possibly resulting in damage. That's why there is a protection so you can only advance and not turn it back.

In the UTC complication however, it is possible to turn back the date. The inconvenience however is that you it is linked to the hour hand so if you want to change a few days, you have quite some turns to make.

Kind regards,

Clemens

Good work Clemens! See the watchmaking class work!

Cheers from Isobars.

The quick date setting with this limitation...

... is huge advantage over the old Cal 8531 movements I have which require countless turns to set the correct date forward or backwards. 15 days of turning can result in repetitive strain injury and the odd blister.