UTC跟LocalTime

var
  g_dtTimeZoneInfo:TIME_ZONE_INFORMATION ;
function GetTimeZoneInfo():boolean ;//取得utc時間
begin
  Result := (TIME_ZONE_ID_INVALID<>GetTimeZoneInformation(g_dtTimeZoneInfo) ) ;
end ;
function LocalTimeToUTC(const dtLocalTime: TDateTime) : TDateTime ;
begin
  Result := IncMinute(dtLocalTime, g_dtTimeZoneInfo.Bias ) ;
end ;

function UTCToLocalTime(const dtUTC: TDateTime) : TDateTime ;
begin
  Result := IncMinute(dtUTC, -g_dtTimeZoneInfo.Bias ) ;
end ;

function UTCNow(): TDateTime;
var
  st: SYSTEMTIME;

begin
  GetSystemTime(st);
  Result:=SystemTimeToDateTime(st);
end;
//---------------------------------------------------------------------------

function UTCDate(): TDateTime;
var
  st: SYSTEMTIME;

begin
  GetSystemTime(st);
  Result:=EncodeDate(st.wYear, st.wMonth, st.wDay);
end;