Julian Date converter: get Julian's date today & Julian's day

The phrase "Julian Date" is used to refer to a date format with the letters yyddd (yy = year, ddd = day) in mainframe and other contexts. Yet, a Julian date technically has multiple meanings. A Julian date is the number of days since the start of the Julian Period, as defined by astronomers (January 1, 4713 BC). Called "Julian day number".

An "ordinal date" is more appropriately referred to as a yyddd (or comparable formats like yyyyddd, yy-ddd) date. On this page, we've used the phrase "Julian Dates," which is what we refer to them as in the mainframe world.

These converters are a modified version from the "U.S. Naval Observatory". Its results have been checked and tested with the results of..

• The "U.S. Naval Observatory" converter.
• The "ssd.jpl.nasa.gov" converter.
• The "Longpela Expertise" converter.

How to use the Converters on this page

• If you want to get the Julian date or Julian day number use the first converter. Choose the day and the month and enter the year.. then click on the convert button.
• If you want to get the gregorian date use the second converter. Enter the julian day number.. then click on the convert button.

• Astronomical Applications Department of the U.S. Naval Observatory.
• Nasa: Jet Propulsion Laboratory - Solar System Dynamics.
• Converting Between Julian Dates and Gregorian Calendar Dates Formulas.
• Julian Day, John Cirillo KDE Documentation.