Nights when the Moon sits above your chosen altitude for enough of the window after sunset.
Site: 31.9583°N, 111.5967°W · elev. 2096 m · times shown in Arizona time (MST, no DST)
Positions use a compact solar/lunar ephemeris (Schlyter, accurate to roughly 1–2 arcminutes for the Moon).
Sunset accounts for atmospheric refraction and the horizon dip from Kitt Peak's 2096 m elevation.
Good for planning; for precision pointing, cross-check critical dates against JPL Horizons.
Year at a glance
Run the calculation to see qualifying nights highlighted across the year.