6/1/96: Please note that there is currently an omission in the leap year calculation (in the BASIC program as well as in the explanatory section), which will affect any calculations for dates after (and some during) the year 2100, and dates before (and some during) the year 1900. Basically, if a year is divisible by 100, it is *not* a leap year... *unless* it is also divisible by 400. Thus, 1900 is not a leap year, 1800 is not, 1700 is not, but 1600 is. In any case, please keep this fact in mind when doing calculations for days far enough into the past or future for this to become a factor...

This page is designed for anyone who has an interest in finding out or calculating moon signs (the phases of the moon). For reasons that the phases of the moon (known as auspices in the following contexts) hold a decent amount of significance in White Wolf's Werewolf: the Apocalypse role playing game, and Rage, the collectible card game based upon W:tA, this page has been hierarchically attached to my Rage Page.

Anyway, for anybody who may be interested in finding out the moon phase for a particular date in history (say, one's birthday), I've written both a BASIC program which will do most of the work for you, and a fairly detailed technical explanation of how to go about doing the calculations manually, oneself.

Of course, I would rather have written the program in C++ instead of in BASIC, but unfortunately, I no longer have access to a C++ compiler, and so would not have been able to test (and debug) the program. And I figure that pretty much everybody has access to some form of BASIC, so while the programming language isn't quite as elegant (efficient), it may actually be of more universal benefit...

Anyway, please note that the accuracy of any calculations (via BASIC, C++, or any other means) of this type is limited both by the nature of the calculations themselves (the more numbers are manipulated, the greater the potential straying from the ideal of "absolute" accuracy), and by the specifics of the source data used (in this case, the length of a synodic month and the dates of the new moons used as reference points). In other words:

(CAUTIONARY NOTE) Don't treat the output from the BASIC program I've written or from any calculations made using the data and methods in the explanatory section as being unequivocably accurate truth. Because it's not. Which is not to say that it'll be completely *inaccurate* either, of course. Just that if you need absolutely precise moon phase data for some important project (or whatever), rather than relying upon calculations, you should instead consult perhaps something like an actual record of historical moon data.

Speaking of which, if anybody has any leads to where one could obtain data like that, please send me some word (my e-mail address is listed below), and I can add the info to this page. Also, I'll then be able to check just what the margin of error is on the calculations my program(s) makes. Also, if anybody has a more accurate (assuming one exists) figure for the length of a synodic month, I'd be interested in that too... For the purposes of calculations like these, the figure I have is probably quite, quite accurate enough, but...

Anyhow, enough intro talk. Here are your links to: