procedure DateDiff(Date1, Date2: TDateTime; var Days, Months, Years: Word);
var
DtSwap: TDateTime;
Day1, Day2, Month1, Month2, Year1, Year2: Word;
begin
if Date1 > Date2 then begin
DtSwap := Date1;
Date1 := Date2;
Date2 := DtSwap;
end;
DecodeDate(Date1, Year1, Month1, Day1);
DecodeDate(Date2, Year2, Month2, Day2);
Years := Year2 - Year1;
Months := 0;
Days := 0;
if Month2 < Month1 then begin
Inc(Months, 12);
Dec(Years);
end;
Inc(Months, Month2 - Month1);
if Day2 < Day1 then begin
Inc(Days, DaysPerMonth(Year1, Month1));
if Months = 0 then begin
Dec(Years);
Months := 11;
end
else Dec(Months);
end;
Inc(Days, Day2 - Day1);
end;