Julian Dates

Because the definition of Julian day varies, the DATE directive offers a great deal of flexibility for representing Julian dates. Many source books define the Julian day as the day of the year, with January 1st being 001, January 2nd being 002, and so forth. If you want to use this definition for Julian day, simply use EEE (day of year) in your date formats.

Other reference books define the Julian day as the number of days since some specific "base date" in the past. This definition is represented in the DATE directive with the letter "J" (for example, a six-digit date field would be preceded with the directive $XFD DATE=JJJJJJ). The default base date for this form of Julian date is January 1, 1900.

You can define your own base date for Julian date calculations by setting the JULIAN_BASE_DATE configuration variable in your acuxdbc.cfg configuration file.