Calendar conversion

The calendar conversion tool allows the conversion of calendar dates in the following calendars:

 Julian / Gregorian calendar

 Gregorian calendar (proleptic)

 Julian calendar

 Islamic calendar

 Hebrew calendar

 Egyptian calendar

 Coptic calendar

 Mayan calendar(s)

In addition the date is given as a Julian day number too.

 

Select Tools->calendar coversion fron the main menu. The calendars dialog appears. Change the date in a calendar, press Enter and the date will change in the other calendars.

 

The calendar conversion tool can be accessed from the Time span dialog too.

 

Notes:

  • In the Julian/Gregorian calendar dates are in the Julian calendar through the date of introduction of the Gregorian calendar, specified by the settings for the current Observer dialog. For clarity this date is shown on top of the field for day specification (1700-03-01 in the example). Note that for all date specifications (e.g. Time span dialog) the Gregorian calendar always begins on 15 October 1582.
  • For all calendars the day is given as a decimal number to make clear, that the date changes at different times in the various calendars. In the Julian and Gregorian calendar the date changes at midnight; in the Islamic and Hebrew calendar the date changes at sunset (6 PM in AE) and in the Egypt calendar (as used by Ptolemy) the date changes at noon.
  • In the proleptic Gregorian calendar dates are always specified according to the rules of the Gregorian calendar, even dates preceding the official introduction of the Gregorian calendar (15 October 1582). So this calendar should be used with great caution to avoid confusion.
  • In the Mayan calendars a date can only specified as a long count date. The date in  the Haab and Tzolkin calendar is given only for informational purposes and ‘read only’.
  • A red symbol left of the fields for year specification indicates that the given year is a leap year. For the Hebrew calendar the length of the specified year is indicated by ‘-‘ (deficient), ± (regular), or ‚‘+‘ (complete).
  • Month names are from Reingold and Dershowitz, Calendrical Calculations, Cambridge University Press 2001

Alcyone Ephemeris Documentation
(C) 2007 Alcyone Software