convert date to julian date using a reference date BC.

I am trying to analyse some french oceanographic data that for some unexplainable reason uses a BC reference date. All the typical matlab functions I use to convert gregorian dates to julian assume the reference date is AD. Can anyone suggest a way to convert a BC gregorian date to a datenumber? Specifically 01 Jan 4713 BC.

Many thanks.

Serena

Answer 1

[Walter Roberson]

juliandate() applied to a datetime object gives that system. Conversion back is

datetime(X, 'convertfrom', 'juliandate')

[Serena Lee]

Thank you. That worked.