dateconversion.zip

The conversion between TDateTime and Julian dates and modified Julian dates in unit dateutils is not compatible with the Delphi versions. After some experimentation, I ascertained that the problem was in two routines, DateTimeToJulianDate TryJulianDateToDateTime. Turns out that the conversion is done for days, excluding any fractions of a day. I have raised a ticket in the Free Pascal bugtracker and hopefully a correction will be applied shortly.

In the meantime, the errors can be seen by comparing the results obtained with dateconversion (download the archive dateconversion.zip) with those from a reputable conversion site such as NASA's Goddard Space Flight Center. If the checkbox Use corrected functions is checked then functions with my proposed corrections will be used instead of those in dateutils.