This happens over the course of a few hours.

Standard date change: a small prong or claw on a wheel grabs that date wheel and push it forward to the next date.

This power is then released when the power in this spring becomes bigger than the power of the spring-loaded date click.

Semi-instantaneous date change: the power is gathered in a spring that is mounted on a wheel.

You can find this in pretty much every high-end watches. This, in turn, will push the date indicator forward one day so quickly that you can’t see it moving with your naked eye. When your watch approaches midnight (within seconds of it, actually), the power in the cam is released suddenly.

Instantaneous date change: the power is slowly gathered in a cam.

To do this, a special mechanism is engaged during the hours preceding and following midnight.ĭepending on the type of movement your watch has, the date change mechanism will be different: The watch movement has to somehow accumulate power to make the date wheel move forward. This is true for mechanical watches (automatic and manually wound) and quartz watches as well.

In order for the watch movement to be able to change the date “overnight”, it needs more power than the one it use to make the hands move. Yet, the movement can’t just change the date instantaneously. The power is delivered by a tiny motor in quartz watches, and by the mainspring and gear train in a mechanical watch. Conversely, the date stays still for at least 18 hours, and they need to change “overnight”. How the date change mechanism workĪs you can see on your watch, the hands move every single second at least (even the hour hand, even if you can’t see it with your naked eye). If you want to be sure, change the date around 5:00 (AM or PM). You could damage the movement of the watch. When not to change the date on a watchĭon’t change the date on your watch between 9:00 PM and 3:00 AM. In worst case scenarios (especially for more affordable quartz movement), you could throw away your beloved watch. In the best case scenario, you could send it for a repair. Changing the date on your watch at the wrong time can damage the movement.

So of course: you need to set the date.īe careful. Or your quartz watch has been sitting in the drawer for weeks and now the date is wrong.

Your automatic watch has run out of juice.

Invicta chronograph