Moon Tool 1.0.1
ftp://ftp.amug.org/pub/mirrors/info-mac/sci/moon-tool-101.hqx
Add this little freeware package to your Apple Menu and you can quickly check the moon's essential stats, like its age in days, hours and minutes, its distance from earth, universal time, and Julian Date (while writing this the JD was 2451005.00450). Perhaps most useful is a picture of the moon in its current phase, such as Full Moon, and the precise times and dates for the other three quarters.
Perhaps there are other routes, but the only way I could readily access Moon Tool was indirectly through reference sites such as Mac's Guide to Freeware (M-O), which is the ftp address listed above. It's a 68K compressed Stuffit file that expands to 145K. No documentation included.