Portuguese Perpetual Calendar double moon phase

Portuguese Perpetual Calendar double moon phase

Are all moon phases correct? Are is there some deviation?

Regards

The moon tends to be fairly consistent with timing of its phases. The IWC perpetual calendar with moon phase is only accurate for 577 years after which it may require an adjustment. A few Euros a month into a sinking fund should cover the cost of the adjustment which, sadly, must be done outside of the warranty period,

I am also contemplating about a Big Pilot Perpetual Calendar.

I have heard stories that the moon phase on some samples could be off (comparing to the actual moon) by a couple of days.

But then, my question is whether the actual moon phase is consistent in all locations on the earth?

Thanks!