// *********************************************************
// 指定日からシステム日付までの経過日数
// 戻り値 : 無し
// *********************************************************
int LboxInfo::DateDiff( SYSTEMTIME *st )
{
	int nRet,nFrom,nTo;
	SYSTEMTIME stTo;
	SYSTEMTIME stNow;

	CopyMemory( &stTo, st, sizeof( SYSTEMTIME ) );
	GetLocalTime( &stNow );

	if ( stTo.wMonth == 1 ) {
		stTo.wYear = stTo.wYear - 1;
		stTo.wMonth = 13;
	}
	if ( stTo.wMonth == 2 ) {
		stTo.wYear = stTo.wYear - 1;
		stTo.wMonth = 14;
	}
	if ( stNow.wMonth == 1 ) {
		stNow.wYear = stNow.wYear - 1;
		stNow.wMonth = 13;
	}
	if ( stNow.wMonth == 2 ) {
		stNow.wYear = stNow.wYear - 1;
		stNow.wMonth = 14;
	}
	
	nFrom = 
		stNow.wYear * 365 + 
		stNow.wYear / 4 -
		stNow.wYear / 100 +
		stNow.wYear / 400 +
		30 * stNow.wMonth +
		( stNow.wMonth + 1 ) * 3 / 5 +
		stNow.wDay - 34;

	nTo = 
		stTo.wYear * 365 + 
		stTo.wYear / 4 -
		stTo.wYear / 100 +
		stTo.wYear / 400 +
		30 * stTo.wMonth +
		( stTo.wMonth + 1 ) * 3 / 5 +
		stTo.wDay - 34;

	nRet = nFrom - nTo;

	return nRet;
}