pom - display the phase of the moon


  pom [-d] [-e] [[[[[[cc]yy]mm]dd]HH]]


The pom utility displays the current phase of the moon. This is useful for selecting software completion target dates, predicting managerial behavior, or determining thoth's current mood. :)

Pom will display the current moon phase, unless a new time is specified on the command line. The parameter's format is similar to the canonical representation used by date(1).

Pom has two modes: "standard" and "enhanced". Standard mode presents a brief description of the moon's phase. It is the default. Enhanced mode shows the phase's date and time, the brief description, and an ASCII art representation of the moon's phase.

Current options:

  -d    Enable debugging.  This calculates phase information every
        hour for a month.

  -e    Enable enhanced mode.  Turns on the ASCII art feature.




Times must be within the range of the Unix epoch.

The local timezone and coordinates are not considered.

Day validation does not consider the current month, or leap days.

The default character cell aspect ratio is likely to be wrong.

There is some jitter in the current calculations. It may only be noticeable while debugging.

The calculations in this version are a few percent different from the original pom.


A lot of the documentation was cribbed from the OpenBSD Reference Manual.

The moon phase calculations were ported from pcal, which is available from <>.


Pom is Copyright 1999 Rocco Caputo <>. All rights reserved. Pom is free software; you may redistribute it and/or modify it under the same terms as Perl itself.