Steve,
When I started out on this pier I received some data completely comprised by strong moonlight. I believe that you advised I needed to put some moonlight restrictions in the comments box.
Now I don't really know how the scheduling software works e.g. what weights to the various observing conditions; cloud, zd, moon phase etc., is it fully automated or is there some human intervention?
Without this detailed knowledge, I have tended to err on the conservative side by requesting moon down or < 25%. My thinking is as follows. This is an OSC camera, and most DSO imaging will be impacted by the moon. An image is only as good as its weakest band - for am OSC thesis the B filter in the Bayer matrix. As a professional, I always used the dictum that the time to call it quits with sky brightness was when the sky counts were doubled over a dark sky. For B band this occurs at roughly Day 5 moon, or around 25%. Hence framing my request as moon down or < 25%.
If we were to use this approach, then 10 nights per lunation fulfil that criterion and a further 8 or so nights still have moon down for an average 50% of time - giving approximately 14nights per lunation - approximately half the time. I am not sure this is what you mean by "only so many days per month", but it doesn't look to back to me.
Ideally it would be helpful to frame the request as "please only take the image when the sky brightness is fainter than 21mag/arcsec", but again I am not sure if the scheduling software has the ability to interpret this.
So, in the absence of better information, my request will still request moon down or