The Project Text Database and Dictionary of Classic Mayan has just released a new WebTool for the calculation and reconstruction of complete and in complete Maya calendar dates. The tool is free and open access via the project website and allows users worldwide to perform calculations of the Maya calendar and astronomical data. The tool not only calculates and reconstructs individual calendar entries, but also the calendarical and astronomical framework of an inscription. Unknown coefficients are entered either with * or a blank field, multiple coefficients are separated with commas " , " (e.g. 1,2,8) and number ranges are defined with " - " (e.g. 1-3,11-13), separated with commas " , ". Results can be exported as CSV, TXT, ODT or PDF. The features are described in a help menu, a description of the tool (in German) can be downloaded from the calendar tool website (via help menu).