The values in this column are the corresponding hour angles of the western ``moonlight'' limits, in decimal degrees.
A simple sanity check on the tabular data is that the ``moonlight'' limits should always be closer to the horizon (i.e., farther from the meridian) than the ``observing'' limits, at every declination. The difference is approximately the angular size of the telescope entrance pupil, as seen from the object that obscures the horizon. If the obscuration is nearby, the difference may be many degrees; if distant, it may be a fraction of a degree.