Guide to Calendar Date Conversion Software

Hermetic Systems publishes seven calendrical programs. Together these convert (or at least display) dates in fifteen calendars. Sometimes two programs will overlap in the calendars that they support. This page allows you to specify which calendars you are interested in and then to find whether there is one calendar program which converts dates in all those calendars, or perhaps two calendar programs which together do so. Check the boxes below for the calendars (or astronomical items or other features) that you are interested in, then click on the 'Submit' button.

Common Era Calendar (Gregorian Calendar) ...................
Julian Calendar ............................................
Julian day numbers .........................................
Ordinal dates (yyyy-ddd) ...................................
Astronomical Julian date ...................................
Chronological Julian date ..................................
Chinese Lunar Calendar .....................................
Chinese Solar Calendar .....................................
Goddess Lunar Calendar .....................................
Meyer-Palmen Solilunar Calendar ............................
Lunar Liberalia Triday Calendar ............................
Solar Liberalia Triday Calendar ............................
Hermetic Leap Week Calendar ................................
Hermetic Lunar Week Calendar ...............................
ISO Week Calendar ..........................................
Maya Long Count ............................................
Maya Tzolkin-Haab ..........................................
Dee(-Cecil) Calendar .......................................
Phase and age of the Moon ..................................
Solstices and equinoxes ....................................
Lunar and solar eclipses ...................................
Calculation of number of days between dates ................
Addition/subtraction of a number of days to/from a date ....
American and European date formats in addition to yyyy-mm-dd
German language in addition to English .....................
Batch processing ...........................................
Calendar date programming language .........................
Celtic Cross-Quarter Days ..................................

Date/Calendar Software

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