What is this good for? I won't believe in explanations like "knowing if it's the right night to harvest mistle-toe" and the like, but want a more rational explanation.
If I've been out at night within the last week, then it's likely I'll have a pretty good idea of what the moon will be like tonight, and if I haven't, is it really likely I'm interested? If I'm interested, it's not the phase I want to know, I want to know much light there will be at what times.
In case I'm planning a landing for the beginning of June, then a moon phase watch won't help me find a suitable night, a calender is better as it's usually got the moon phases marked. But that's not enough, an ephemeris is also needed as the times when the moon rises and sets also has to be considered. A nearly full moon which rises in the morning won't help much.
Of course it can be seen as simply an animated decoration. (As in "We can do this, so let's!")
Or perhaps "moon phase" is a euphemism for keeping track of menstruation cycles? Makes sort of sense as those who go through them, and therefore don't need an external reminder, seem to seldom wear watches with this feature.
Document created 2001 Oct 11 content reviewed 2003 Jan 08 by Urban