private void Form1_Load(object sender, EventArgs e)
{
    FarPoint.Win.Spread.CellType.DateTimeCellType dateTime = new FarPoint.Win.Spread.CellType.DateTimeCellType();
    dateTime.DateTimeFormat = FarPoint.Win.Spread.CellType.DateTimeFormat.UserDefined;
    dateTime.UserDefinedFormat = "yyyy-MM-dd h:mm";

    fpSpread1.ActiveSheet.Cells["A1"].CellType = dateTime;

    // 데이터 입력
    DateTime dt = new DateTime(2022, 05, 23, 6, 50, 0);
    fpSpread1.ActiveSheet.Cells["A1"].Value = dt;
}

private void button1_Click(object sender, EventArgs e)
{
    fpSpread1.SaveExcel("D:\\Sample\\Excel.xlsx", FarPoint.Excel.ExcelSaveFlags.UseOOXMLFormat);
}