private void CheckDateTimeNumFmts(List<XlsxNumFmt> list)
		{
			if (list.Count == 0) return;

			foreach (XlsxNumFmt numFmt in list)
			{
				if (string.IsNullOrEmpty(numFmt.FormatCode)) continue;
				string fc = numFmt.FormatCode.ToLower();

				int pos;
				while ((pos = fc.IndexOf('"')) > 0)
				{
					int endPos = fc.IndexOf('"', pos + 1);

					if (endPos > 0) fc = fc.Remove(pos, endPos - pos + 1);
				}

				//it should only detect it as a date if it contains
				//dd mm mmm yy yyyy
				//h hh ss
				//AM PM
				//and only if these appear as "words" so either contained in [ ]
				//or delimted in someway
				//updated to not detect as date if format contains a #
				var formatReader = new FormatReader() {FormatString = fc};
				if (formatReader.IsDateFormatString())
				{
					_defaultDateTimeStyles.Add(numFmt.Id);
				}
			}
		}
		private  object tryConvertOADateTime(double value, ushort XFormat)
		{
		    ushort format = 0;
            if (XFormat >= 0 && XFormat < m_globals.ExtendedFormats.Count)
            {
                var rec = m_globals.ExtendedFormats[XFormat];
                switch (rec.ID)
                {
                    case BIFFRECORDTYPE.XF_V2:
                        format = (ushort) (rec.ReadByte(2) & 0x3F);
                        break;
                    case BIFFRECORDTYPE.XF_V3:
                          if ((rec.ReadByte(3) & 4) == 0)
                            return value;
                        format = rec.ReadByte(1);
                        break;
                    case BIFFRECORDTYPE.XF_V4:
                        if ((rec.ReadByte(5) & 4) == 0)
                            return value;
                        format = rec.ReadByte(1);
                        break;
                    
                    default:
                        if ((rec.ReadByte(m_globals.Sheets[m_globals.Sheets.Count-1].IsV8 ? 9 : 7) & 4) == 0)
                            return value;
                        
                        format = rec.ReadUInt16(2);
                        break;
                }
            }
			else
            {
            	format = XFormat;
            }

           
            switch (format)
            {
                // numeric built in formats
                case 0: //"General";
                case 1: //"0";
                case 2: //"0.00";
                case 3: //"#,##0";
                case 4: //"#,##0.00";
                case 5: //"\"$\"#,##0_);(\"$\"#,##0)";
                case 6: //"\"$\"#,##0_);[Red](\"$\"#,##0)";
                case 7: //"\"$\"#,##0.00_);(\"$\"#,##0.00)";
                case 8: //"\"$\"#,##0.00_);[Red](\"$\"#,##0.00)";
                case 9: //"0%";
                case 10: //"0.00%";
                case 11: //"0.00E+00";
                case 12: //"# ?/?";
                case 13: //"# ??/??";
                case 0x30:// "##0.0E+0";
               
                case 0x25:// "_(#,##0_);(#,##0)";
                case 0x26:// "_(#,##0_);[Red](#,##0)";
                case 0x27:// "_(#,##0.00_);(#,##0.00)";
                case 40:// "_(#,##0.00_);[Red](#,##0.00)";
                case 0x29:// "_(\"$\"* #,##0_);_(\"$\"* (#,##0);_(\"$\"* \"-\"_);_(@_)";
                case 0x2a:// "_(\"$\"* #,##0_);_(\"$\"* (#,##0);_(\"$\"* \"-\"_);_(@_)";
                case 0x2b:// "_(\"$\"* #,##0.00_);_(\"$\"* (#,##0.00);_(\"$\"* \"-\"??_);_(@_)";
                case 0x2c:// "_(* #,##0.00_);_(* (#,##0.00);_(* \"-\"??_);_(@_)";
                    return value;

                    // date formats
                case 14: //this.GetDefaultDateFormat();
                case 15: //"D-MM-YY";
                case 0x10: // "D-MMM";
                case 0x11: // "MMM-YY";
                case 0x12: // "h:mm AM/PM";
                case 0x13: // "h:mm:ss AM/PM";
                case 20: // "h:mm";
                case 0x15: // "h:mm:ss";
                case 0x16: // string.Format("{0} {1}", this.GetDefaultDateFormat(), this.GetDefaultTimeFormat());
                   
                case 0x2d: // "mm:ss";
                case 0x2e: // "[h]:mm:ss";
                case 0x2f: // "mm:ss.0";
                    return Helpers.ConvertFromOATime(value);
                 case 0x31:// "@";
                    return value.ToString();

                default:
                    XlsBiffFormatString fmtString;
                    if (m_globals.Formats.TryGetValue(format, out fmtString) )
                    {
                        var fmt = fmtString.Value;
                    	var formatReader = new FormatReader() {FormatString = fmt};
						if (formatReader.IsDateFormatString())
                            return Helpers.ConvertFromOATime(value); 

                    }
                    return value;



            }

		    
		}