GMT 时间格式转换到 TDateTime (Delphi)

 //GMT 时间格式转换到 TDateTime
 //忽略时区
 function GMT2DateTime(const pSour:PAnsiChar):TDateTime;

   function GetMonthDig(const Value:PAnsiChar):Integer;
   const
     MonthDig:array[..] of PAnsiChar =
     (
      'Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'
     );
   var
     Index:Integer;
   begin
     Result := ;
     for Index :=  to  do
     begin
       if AnsiStrIComp(Value,MonthDig[Index]) =  then
       begin
         Result := Index;
         Break;
       end;
     end;
   end;

 var
   A:array[..] of Ansichar;
   P1,P2:PAnsiChar;
   Len:Integer;
   wDay,wMonth,wYear,wHour,wMinute,wSec:Word;
   D:TDateTime;
 begin
  //P1 := '  Mon, 12 Aug 2013 16:20:35 GMT';
   Result := ;
   P1 := pSour;
   P2 := @A[];
   Len := ;
   while((Len > ) and (P1^ <>#)) do
   begin
     P2^ := P1^;
     Inc(P1);
     Inc(p2);
     Dec(Len);
   end;
   P2^ := #;

   P1 := @A[];
   while((P1^<>',') and (P1^ <>#)) do Inc(P1);Inc(p1);

   //
   while((P1^ <> #) and (P1^ <>#)) do Inc(P1);Inc(p1);P2 := P1;
   while((P2^ <> #) and (P2^ <>#)) do Inc(P2); P2^ := #;
   wDay := StrToIntDef(P1,-);

   //Aug
   P1 := P2; Inc(P1);P2 := P1;
   while( (P2^<>#) and (P2^ <>#)) do Inc(P2);P2^ := #;
   wMonth := GetMonthDig(P1);
   if wMonth =  then
     Exit;

   //
   P1 := P2; Inc(P1);P2 := P1;
   while( (P2^<>#) and (P2^ <>#) ) do Inc(P2);P2^ := #;
   wYear := StrToIntDef(P1,-);
   if wYear =  then
     Exit;

   //Hour
   P1 := P2; Inc(P1);P2 := P1;
   while((P2^<>':') and (P2^ <>#)) do Inc(P2);P2^ := #;
   wHour := StrToIntDef(P1,-);
   if wHour <  then
     Exit;

   //Min
   P1 := P2; Inc(P1);P2 := P1;
   while((P2^<>':') and (P2^ <>#)) do Inc(P2);P2^ := #;
   wMinute := StrToIntDef(P1,-);
   if wMinute <  then
      Exit;

   //Sec
   P1 := P2; Inc(P1);P2 := P1;
   while((P2^<>#) and (P2^ <>#)) do Inc(P2);P2^ := #;
   wSec := StrToIntDef(P1,-);
   if wSec <  then
     Exit;

   Result := EnCodeDateTime(wYear,wMonth,wDay,wHour,wMinute,wSec,);

 end;

TDateTime 转换成 GMT 时间格式

 function DateTimeToGMT(const ADate:TDateTime):string;
 const
   WEEK:array[..] of PChar = ('Sun','Mon','Tues','Wed','Thur','Fri','Sat');
   MonthDig:array[..] of PChar =
     ('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');

 var
   wWeek,wYear,wMonth,wDay,wHour,wMin,wSec,wMilliSec:Word;
   A:array[..] of AnsiChar;
   P1,P2:PAnsiChar;
   sWeek,sMonth:string;
 begin
   DecodeDateTime(ADate,wYear,wMonth,wDay,wHour,wMin,wSec,wMilliSec);
   wWeek := DayOfWeek(ADate);
   sWeek  := WEEK[wWeek];
   sMonth := MonthDig[wMonth];
   Result := Format(' %s, %d %s %d %d:%d:%d GMT',[sWeek,wDay,sMonth,wYear,wHour,wMin,wSec]);
 end;