//日历日、工作日、交易日的日期偏移计算
public WindData tdaysoffset(string startTime, int offset, string options)
{
checkConnection();
object ocodes, ofields, otimes, odata;
int errCode;
odata = wdc.tdaysoffset_syn(startTime, offset, options, out ocodes, out ofields, out otimes, out errCode);
return(formatWD(ocodes, ofields, otimes, odata, errCode));
}