Chac is a complete, accurate Maya calendar application. It can find Maya calendar dates based on today’s date, any date, a Long Count, Tzolk’in, Haab’, Calendar Round, Julian day number, distance number, long reckoning , seatings in the cycle of God K, and convert between the Julian and Gregorian calendars. Chac can find the next heliacal or cosmical rising or setting of Venus and the visibility of the current inscription or date.

You can use a large range of correlation constants, any one of the six possible moon numbers, astronomical or historical dating, any of the four Year Bearer systems and appearance of the new moon or the disappearance of the waning moon. Chac can display a Long Count with head or symbolic glyphs. Chac draws the results as a complete Maya calendar inscription.

An inscription with its preferences can be saved in Chac’s file format or it can be saved as graphics in TIFF, PDF, JPG, PNG, JP2, or BMP formats. An inscription can also be copied to the clipboard where it will be posted as PDF and TIFF.