Import Data From excel into Sql Server using C# and Eppplus

Question

I Have a Problem with my project ,

 

It's a Employee absence application,

 

one of the features is  upload schedule, the people from human resource department ,can upload schedule of each employee by using this form /features, but there is some problem with this features,

 

in some case people can upload excel file with wrong date format 

 

 

but in excel file format cells like this

 

when i upload this excel file ,it's failed ,

 

but i try to changes into format cells like this 

 

 

and it was succesfully uploaded ,

it  become a problem because not only me use this application, 

 

how can i solve this?

this is my code

protected void excel(object sender, EventArgs e) {
 using(ExcelPackage package = new ExcelPackage(existingFile)) //mypath
 {
  ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
  int colCount = worksheet.Dimension.End.Column;
  int rowCount = worksheet.Dimension.End.Row;
  table.Columns.Add("Schedule_Date", typeof(DateTime));
  for (int i = 2; i <= rowCount; i++) {
   if (!worksheet.Cells[i, 1].Text.ToString().Equals("")) {

    if (!worksheet.Cells[i, 2].Text.ToString().Equals("")) {
     if (!worksheet.Cells[i, 3].Text.ToString().Equals("")) {
      DateTime d;
      string[] formats = {
       "MM/dd/yyyy",
       "M/d/yyyy",
       "MM/d/yyyy",
       "M/dd/yyyy",
       "MM/dd/yyyy hh:mm:ss",
       "MM/dd/yyyy hh:mm:ss tt",
       "M/dd/yyyy hh:mm:ss tt",
       "M/d/yyyy hh:mm:ss tt",
       "MM/d/yyyy hh:mm:ss tt",
       "MM/dd/yyyy h:mm:ss",
       "MM/dd/yyyy",
       "M/d/yyyy h:mm:ss"
      };
      TableRow row = new TableRow();
      TableCell cell1 = new TableCell();
      TableCell cell2 = new TableCell();

      string schedule_date = Convert.ToString(worksheet.Cells[i, 3].Value.ToString());

      string currentrow = worksheet.Cells[i, 1].Text.ToString() + worksheet.Cells[i, 3].Text.ToString();
      for (int j = i + 1; j < rowCount + 1; j++) {
       string nextrow = worksheet.Cells[j, 1].Text.ToString() + worksheet.Cells[j, 3].Text.ToString();
       if (!currentrow.Equals(nextrow)) {
        if (DateTime.TryParseExact(schedule_date, formats, new CultureInfo("en-US"), DateTimeStyles.None, out d)) {
         count += 0;
         string labelmonth = ddlTest.SelectedValue.ToString();
         //   string shift = worksheet.Cells[i, 2].Value.ToString();
         string employee_id = worksheet.Cells[i, 1].Value.ToString();
         string user = Session["LogedUserID"].ToString();
         bool validatemonth = ddlTest.SelectedValue.ToString() == DateTime.Parse(worksheet.Cells[i, 3].Value.ToString()).ToString("MM");
         if (validatemonth.Equals(false)) {
          count += 1;
          cell1.Text = "Line" + i + "  "; // +employee_id + " " + schedule_date;//" "  + Convert.ToDateTime(schedule_date).ToString("MM/dd/yyyy");//+ " Baris ke " + i + " Bulan Tidak Sesuai";
          cell2.Text = "Invalid Month ";
          row.Cells.Add(cell1);
          row.Cells.Add(cell2);
          mytable.Rows.Add(row);
         } else {
          if (!shifts.Equals(sshift)) {
           count += 1;
           count += 1;
           cell1.Text = "Line " + i + "  "; // +employee_id + " " + schedule_date;//" "  + Convert.ToDateTime(schedule_date).ToString("MM/dd/yyyy");//+ " Baris ke " + i + " Bulan Tidak Sesuai";
           cell2.Text = "No Shift";
           row.Cells.Add(cell1);
           row.Cells.Add(cell2);
           mytable.Rows.Add(row);
          }
         }
        } else {
         count += 1;
         cell1.Text = "Line " + i + " " + Convert.ToString(schedule_date); //.ToString("MM/dd/yyyy");
         cell2.Text = "Invalid Format";
         row.Cells.Add(cell1);
         row.Cells.Add(cell2);
         mytable.Rows.Add(row);
        }
       } else {
        cell1.Text = " Line  " + i.ToString();
        cell2.Text = "same value with  " + j.ToString();
        row.Cells.Add(cell1);
        row.Cells.Add(cell2);
        mytable.Rows.Add(row);
        count += 1;
       }
      }
     }
    }
   }
  }
 }
 if (count.Equals(0)) {
  insert();
  File.Move(tempfile, arsipfile);
 } else {
  Response.Write("<script>window.alert('Data Tidak Tersimpan')</script>");
  File.Delete(tempfile);
 }
}
else {
 File.Delete(tempfile);
 Response.Write("<script>window.alert('Pilih Bulan Terlebih dahulu')</script>");
}
}
} else {
 Response.Write("<script>window.alert('File Belum Di Upload')</script>");
}
}