This program may be used: • To display the current phase of the Moon. • To calculate the phase of the Moon for any time in the past or future (within a 9000-year period). • To convert between dates in various calendars: Two solar calendars (the Gregorian Calendar and the Julian Calendar) and five lunar calendars (the Archetypes Calendar, the Meyer-Palmen Solilunar Calendar, the McKenna-Meyer Goddess Calendar, the Lunar Liberalia Triday Calendar and the Hermetic Lunar Week Calendar). • To move forward or backward from a given date (and time) either by a period such as one month (in any of the lunar calendars) or by any number of days. • To search for the date of the next or previous full moon, dark moon or first or last quarter. • To search for the date of the next or previous eclipse of a certain type: solar, total solar, annular solar, lunar, partial lunar or penumbral lunar.
This software gives eclipse dates in both the Common Era (a.k.a. Gregorian) Calendar (CE) and the Julian Calendar (JC) — or more exactly, in the proleptic versions of these (which allow dates prior to the historical date of first use of the calendar). Some websites giving eclipse dates use a calendar-switchover, according to which the dates of eclipses occurring after the date of the official introduction of the Gregorian Calendar (October 15, 1582) are given in the Gregorian Calendar, and dates of eclipses occurring before this date are given in the Julian Calendar — sometimes with no indication of which calendar is being used. Thus if comparing eclipse dates given by this software with dates available on other websites one must be careful as to whether the dates are in the Gregorian Calendar or in the Julian Calendar (and don't forget about astronomical year numbering).