[fpc-devel] File Dates

[Marco van de Voort]

> Michael Van Canneyt wrote:
> > routines. There are a lot of TDateTime routines in the RTL, they would
> > all be at your disposal.
> 
> Okay, I'll use TDateTime internally, with the following questions:
> 
> FPC defines 1900-1-1 as the start date, whereas Delphi defines
> 1899-12-30 as the start date - note: neither 1900 nor dec. 31!
> This requires different constants for converting a Unix date into
> TDateTime, or portable procedures. What's the suggested way for such
> conversions?

IIRC there are some problems that lead to multiple definitions for julian dates:
- original julian starts at noon, so the exact moment taken for the first day
   could be before and after.
- leaphandling for the year 1900 was not uniform IIRC over all calendars

But I don't know why FPC's definition is not the same as delphi's :-)