时间相减简单问题

[My_first]

T1='2005-7-19 6:00:00'
T2='8:00:00'

哪个函数可以得到下面的结果.
T1-T2=
'2005-7-18 22:00:00'

thx

[hnhb]

如何知道你的T2是哪天呢？
UP一下....

[My_first]

T2不是天数，是小时.
指8小时。
用now()-8小时.

[僵哥]

T1='2005-7-19 6:00:00'
T2='8:00:00'
-------------------------------------------
function func(const T1,T2:String):String;
var
d1:TDateTime;
d2:TDateTime;
begin
d1:=StrToDateTime(T1);
d2:=StrToTime(T2);
Result:=DateTimeToStr(d1+d2);
end;

[merkey2002]

procedure TForm1.Button1Click(Sender: TObject);
var
iDate:TDateTime;
iTime:TDateTime;
begin
iDate:=strtodatetime('2005-7-19 6:00:00');
iTime:=strtodatetime('8:00:00');
showmessage(datetimetostr(iDate));
iDate:=iDate-iTime;
showmessage(datetimetostr(iDate));
end;

//时间就是double型，直接加减就OK

[僵哥]

哈哈，不好意思，减写成加了^_^
======================================
function func(const T1,T2:String):String;
var
d1:TDateTime;
d2:TDateTime;
begin
d1:=StrToDateTime(T1);
d2:=StrToTime(T2);
Result:=DateTimeToStr(d1-d2);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
ShowMessage(func('2005-7-19 6:00:00','8:00:00'));
end;

[僵哥]

begin
ShortDateFormat:='yyyy-m-d';
DateSeparator:='-';
ShowMessage(DateTimeToStr(StrToDateTime('2005-7-19 6:00:00')-StrToTime('8:00:00')));
end;