Format type date, text, number when export excel in datagridview C#

Please help me: I can't format Date (dd/mm/yyyy), Text, Number of Columns in Datagridview C# when Export Excel.

private void btnExportExcel_Click(object sender, EventArgs e)
        {
            if (dgvGF1111.Rows.Count > 0)

            {
                Microsoft.Office.Interop.Excel.Application xcelApp = new Microsoft.Office.Interop.Excel.Application();
                xcelApp.Application.Workbooks.Add(Type.Missing);

                for (int i = 1; i < dgvGF1111.Columns.Count + 1; i++)
                {
                    xcelApp.Cells[1, i] = dgvGF1111.Columns[i - 1].HeaderText;
                }

                for (int i = 0; i < dgvGF1111.Rows.Count; i++)

                {
                    for (int j = 0; j < dgvGF1111.Columns.Count; j++)

                    {
                        if (i < dgvGF1111.Rows.Count)
                        {
                            xcelApp.Cells[i + 2, j + 1] = dgvGF1111.Rows[i].Cells[j].Value.ToString();
                            //xcelApp.Cells[i+2, 3] = Convert.ToDateTime(dgvGF1111.Rows[2].Cells[3].Value);
                        }
                    }
                }
                xcelApp.Columns.AutoFit();
                xcelApp.Visible = true;
            }
        }

What I have tried:

Format Date, Text, number,.... when Export Excel in Datagridview C#