[日付型への変換]

それぞれの型を、日付型に変換します。

program tips0011;
{$APPTYPE CONSOLE}
uses SysUtils,Variants;
var
 a:Integer;
 b:Double;
 c:String;
 d,e,f:TDateTime;
begin
 a:=-5;
 b:=123.123;
 c:='2009/05/24 10:28';

 d:=VarToDateTime(a);
 e:=TDateTime(b);
 f:=StrToDateTime(c);

 WriteLn(DateTimeToStr(d));
 WriteLn(DateTimeToStr(e));
 WriteLn(DateTimeToStr(f));
end.

dcc32 tips0011.pas 
tips0011.exe  > tips0011.txt
pause

1899/12/25
1900/05/02 2:57:07
2009/05/24 10:28:00