This closes #1830, closes #1831, and closes #1833

- Fix a v2.8.1 regression bug, auto filter does not work in the LibreOffice
- Fix a v2.8.1 regression bug, support to adjust data validation with multiple cell range
- Fix incorrect result data type of the DATE formula function
- Update the unit tests

adjust.go

@@ -237,18 +237,19 @@ func (f *File) adjustSingleRowFormulas(sheet, sheetN string, r *xlsxRow, num, of
 }
 
 // adjustCellRef provides a function to adjust cell reference.
-func (f *File) adjustCellRef(ref string, dir adjustDirection, num, offset int) (string, bool, error) {
+func (f *File) adjustCellRef(cellRef string, dir adjustDirection, num, offset int) (string, error) {
+	var SQRef []string
+	for _, ref := range strings.Split(cellRef, " ") {
 		if !strings.Contains(ref, ":") {
 			ref += ":" + ref
 		}
-	var delete bool
 		coordinates, err := rangeRefToCoordinates(ref)
 		if err != nil {
-		return ref, delete, err
+			return "", err
 		}
 		if dir == columns {
 			if offset < 0 && coordinates[0] == coordinates[2] {
-			delete = true
+				continue
 			}
 			if coordinates[0] >= num {
 				coordinates[0] += offset
@@ -258,7 +259,7 @@ func (f *File) adjustCellRef(ref string, dir adjustDirection, num, offset int) (
 			}
 		} else {
 			if offset < 0 && coordinates[1] == coordinates[3] {
-			delete = true
+				continue
 			}
 			if coordinates[1] >= num {
 				coordinates[1] += offset
@@ -267,8 +268,12 @@ func (f *File) adjustCellRef(ref string, dir adjustDirection, num, offset int) (
 				coordinates[3] += offset
 			}
 		}
-	ref, err = coordinatesToRangeRef(coordinates)
+		if ref, err = coordinatesToRangeRef(coordinates); err != nil {
-	return ref, delete, err
+			return "", err
+		}
+		SQRef = append(SQRef, ref)
+	}
+	return strings.Join(SQRef, " "), nil
 }
 
 // adjustFormula provides a function to adjust formula reference and shared
@@ -284,7 +289,7 @@ func (f *File) adjustFormula(sheet, sheetN string, cell *xlsxC, dir adjustDirect
 		return nil
 	}
 	if cell.F.Ref != "" && sheet == sheetN {
-		if cell.F.Ref, _, err = f.adjustCellRef(cell.F.Ref, dir, num, offset); err != nil {
+		if cell.F.Ref, err = f.adjustCellRef(cell.F.Ref, dir, num, offset); err != nil {
 			return err
 		}
 		if si && cell.F.Si != nil {
@@ -932,11 +937,11 @@ func (f *File) adjustConditionalFormats(ws *xlsxWorksheet, sheet string, dir adj
 		if cf == nil {
 			continue
 		}
-		ref, del, err := f.adjustCellRef(cf.SQRef, dir, num, offset)
+		ref, err := f.adjustCellRef(cf.SQRef, dir, num, offset)
 		if err != nil {
 			return err
 		}
-		if del {
+		if ref == "" {
 			ws.ConditionalFormatting = append(ws.ConditionalFormatting[:i],
 				ws.ConditionalFormatting[i+1:]...)
 			i--
@@ -967,11 +972,11 @@ func (f *File) adjustDataValidations(ws *xlsxWorksheet, sheet string, dir adjust
 				continue
 			}
 			if sheet == sheetN {
-				ref, del, err := f.adjustCellRef(dv.Sqref, dir, num, offset)
+				ref, err := f.adjustCellRef(dv.Sqref, dir, num, offset)
 				if err != nil {
 					return err
 				}
-				if del {
+				if ref == "" {
 					worksheet.DataValidations.DataValidation = append(worksheet.DataValidations.DataValidation[:i],
 						worksheet.DataValidations.DataValidation[i+1:]...)
 					i--

adjust_test.go

@@ -1059,6 +1059,16 @@ func TestAdjustDataValidations(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, "\"A<,B>,C\",D\t,E',F\"", dvs[2].Formula1)
 
+	// Test adjust data validation with multiple cell range
+	dv = NewDataValidation(true)
+	dv.Sqref = "G1:G3 H1:H3"
+	assert.NoError(t, dv.SetDropList([]string{"1", "2", "3"}))
+	assert.NoError(t, f.AddDataValidation("Sheet1", dv))
+	assert.NoError(t, f.InsertRows("Sheet1", 2, 1))
+	dvs, err = f.GetDataValidations("Sheet1")
+	assert.NoError(t, err)
+	assert.Equal(t, "G1:G4 H1:H4", dvs[3].Sqref)
+
 	dv = NewDataValidation(true)
 	dv.Sqref = "C5:D6"
 	assert.NoError(t, dv.SetRange("Sheet1!A1048576", "Sheet1!XFD1", DataValidationTypeWhole, DataValidationOperatorBetween))

calc.go

@@ -12081,7 +12081,7 @@ func (fn *formulaFuncs) DATE(argsList *list.List) formulaArg {
 		return newErrorFormulaArg(formulaErrorVALUE, "DATE requires 3 number arguments")
 	}
 	d := makeDate(int(year.Number), time.Month(month.Number), int(day.Number))
-	return newStringFormulaArg(timeFromExcelTime(daysBetween(excelMinTime1900.Unix(), d)+1, false).String())
+	return newNumberFormulaArg(daysBetween(excelMinTime1900.Unix(), d) + 1)
 }
 
 // calcDateDif is an implementation of the formula function DATEDIF,

calc_test.go

@@ -1540,8 +1540,9 @@ func TestCalcCellValue(t *testing.T) {
 		"=XOR(1>0,0>1,INT(0),INT(1),A1:A4,2)": "FALSE",
 		// Date and Time Functions
 		// DATE
-		"=DATE(2020,10,21)": "2020-10-21 00:00:00 +0000 UTC",
+		"=DATE(2020,10,21)":   "44125",
-		"=DATE(1900,1,1)":   "1899-12-31 00:00:00 +0000 UTC",
+		"=DATE(2020,10,21)+1": "44126",
+		"=DATE(1900,1,1)":     "1",
 		// DATEDIF
 		"=DATEDIF(43101,43101,\"D\")":  "0",
 		"=DATEDIF(43101,43891,\"d\")":  "790",

table.go

@@ -474,7 +474,7 @@ func (f *File) AutoFilter(sheet, rangeRef string, opts []AutoFilterOptions) erro
 	}
 	filterRange := fmt.Sprintf("'%s'!%s", sheet, ref)
 	d := xlsxDefinedName{
-		Name:         builtInDefinedNames[2],
+		Name:         builtInDefinedNames[3],
 		Hidden:       true,
 		LocalSheetID: intPtr(sheetID),
 		Data:         filterRange,
@@ -490,7 +490,7 @@ func (f *File) AutoFilter(sheet, rangeRef string, opts []AutoFilterOptions) erro
 			if definedName.LocalSheetID != nil {
 				localSheetID = *definedName.LocalSheetID
 			}
-			if definedName.Name == builtInDefinedNames[2] && localSheetID == sheetID && definedName.Hidden {
+			if definedName.Name == builtInDefinedNames[3] && localSheetID == sheetID && definedName.Hidden {
 				wb.DefinedNames.DefinedName[idx].Data = filterRange
 				definedNameExists = true
 			}

table_test.go

@@ -174,7 +174,7 @@ func TestAutoFilter(t *testing.T) {
 	assert.EqualError(t, f.AutoFilter("Sheet1", "D4:B1", nil), "XML syntax error on line 1: invalid UTF-8")
 	// Test add auto filter with empty local sheet ID
 	f = NewFile()
-	f.WorkBook = &xlsxWorkbook{DefinedNames: &xlsxDefinedNames{DefinedName: []xlsxDefinedName{{Name: builtInDefinedNames[2], Hidden: true}}}}
+	f.WorkBook = &xlsxWorkbook{DefinedNames: &xlsxDefinedNames{DefinedName: []xlsxDefinedName{{Name: builtInDefinedNames[3], Hidden: true}}}}
 	assert.NoError(t, f.AutoFilter("Sheet1", "A1:B1", nil))
 }