Ideas:

1. This glyph is identical in appearance with the one in Sunday. Does that imply we should 'read' it in an identical way? Probably not, to read you must rely on what is before and what is after.  The context is always indispensable. That is why I try to proceed with this investigation by closely analysing the parts of a whole which at least to some extent is known, like the week, the month and the year.

2. So what does this glyph mean? Possibly it means that the moon is very useful because it does shine in the night.

The sun does not shine in the night. Where is he? Clearly he is below the ground, as he descended in the west and is going to ascend in the east after having travelled under the earth. It is as if the sun dies in the evening, rejuvenates during the night and is born fresh again in the morning.