diff --git a/calc.go b/calc.go
index badd30e..59131d8 100644
--- a/calc.go
+++ b/calc.go
@@ -2849,7 +2849,7 @@ func (fn *formulaFuncs) ARABIC(argsList *list.List) formulaArg {
 		return newErrorFormulaArg(formulaErrorVALUE, "ARABIC requires 1 numeric argument")
 	}
 	text := argsList.Front().Value.(formulaArg).Value()
-	if len(text) > 255 {
+	if len(text) > MaxFieldLength {
 		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
 	}
 	text = strings.ToUpper(text)
@@ -7400,47 +7400,12 @@ func (fn *formulaFuncs) DAYS(argsList *list.List) formulaArg {
 	if argsList.Len() != 2 {
 		return newErrorFormulaArg(formulaErrorVALUE, "DAYS requires 2 arguments")
 	}
-	var end, start float64
-	endArg, startArg := argsList.Front().Value.(formulaArg), argsList.Back().Value.(formulaArg)
-	switch endArg.Type {
-	case ArgNumber:
-		end = endArg.Number
-	case ArgString:
-		endNum := endArg.ToNumber()
-		if endNum.Type == ArgNumber {
-			end = endNum.Number
-		} else {
-			args := list.New()
-			args.PushBack(endArg)
-			endValue := fn.DATEVALUE(args)
-			if endValue.Type == ArgError {
-				return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-			}
-			end = endValue.Number
-		}
-	default:
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
-	switch startArg.Type {
-	case ArgNumber:
-		start = startArg.Number
-	case ArgString:
-		startNum := startArg.ToNumber()
-		if startNum.Type == ArgNumber {
-			start = startNum.Number
-		} else {
-			args := list.New()
-			args.PushBack(startArg)
-			startValue := fn.DATEVALUE(args)
-			if startValue.Type == ArgError {
-				return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-			}
-			start = startValue.Number
-		}
-	default:
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	return newNumberFormulaArg(end - start)
+	end, start := args.List[0], args.List[1]
+	return newNumberFormulaArg(end.Number - start.Number)
 }
 
 // ISOWEEKNUM function returns the ISO week number of a supplied date. The
@@ -7695,28 +7660,18 @@ func (fn *formulaFuncs) YEARFRAC(argsList *list.List) formulaArg {
 	if argsList.Len() != 2 && argsList.Len() != 3 {
 		return newErrorFormulaArg(formulaErrorVALUE, "YEARFRAC requires 3 or 4 arguments")
 	}
-	var basisArg formulaArg
-	startArg, endArg := argsList.Front().Value.(formulaArg).ToNumber(), argsList.Front().Next().Value.(formulaArg).ToNumber()
-	args := list.New().Init()
-	if startArg.Type != ArgNumber {
-		args.PushBack(argsList.Front().Value.(formulaArg))
-		if startArg = fn.DATEVALUE(args); startArg.Type != ArgNumber {
-			return startArg
-		}
-	}
-	if endArg.Type != ArgNumber {
-		args.Init()
-		args.PushBack(argsList.Front().Next().Value.(formulaArg))
-		if endArg = fn.DATEVALUE(args); endArg.Type != ArgNumber {
-			return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-		}
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	start, end := args.List[0], args.List[1]
+	basis := newNumberFormulaArg(0)
 	if argsList.Len() == 3 {
-		if basisArg = argsList.Back().Value.(formulaArg).ToNumber(); basisArg.Type != ArgNumber {
-			return basisArg
+		if basis = argsList.Back().Value.(formulaArg).ToNumber(); basis.Type != ArgNumber {
+			return basis
 		}
 	}
-	return yearFrac(startArg.Number, endArg.Number, int(basisArg.Number))
+	return yearFrac(start.Number, end.Number, int(basis.Number))
 }
 
 // NOW function returns the current date and time. The function receives no
@@ -7859,7 +7814,7 @@ func (fn *formulaFuncs) CHAR(argsList *list.List) formulaArg {
 		return arg
 	}
 	num := int(arg.Number)
-	if num < 0 || num > 255 {
+	if num < 0 || num > MaxFieldLength {
 		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
 	}
 	return newStringFormulaArg(fmt.Sprintf("%c", num))
@@ -9413,24 +9368,11 @@ func (fn *formulaFuncs) ACCRINT(argsList *list.List) formulaArg {
 	if argsList.Len() > 8 {
 		return newErrorFormulaArg(formulaErrorVALUE, "ACCRINT allows at most 8 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	issue := fn.DATEVALUE(args)
-	if issue.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	fi := fn.DATEVALUE(args)
-	if fi.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Next().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(3, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	issue, settlement := args.List[0], args.List[2]
 	rate := argsList.Front().Next().Next().Next().Value.(formulaArg).ToNumber()
 	par := argsList.Front().Next().Next().Next().Next().Value.(formulaArg).ToNumber()
 	frequency := argsList.Front().Next().Next().Next().Next().Next().Value.(formulaArg).ToNumber()
@@ -9468,18 +9410,11 @@ func (fn *formulaFuncs) ACCRINTM(argsList *list.List) formulaArg {
 	if argsList.Len() != 4 && argsList.Len() != 5 {
 		return newErrorFormulaArg(formulaErrorVALUE, "ACCRINTM requires 4 or 5 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	issue := fn.DATEVALUE(args)
-	if issue.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	issue, settlement := args.List[0], args.List[1]
 	if settlement.Number < issue.Number {
 		return newErrorFormulaArg(formulaErrorNUM, formulaErrorNUM)
 	}
@@ -9644,24 +9579,11 @@ func (fn *formulaFuncs) prepareCouponArgs(name string, argsList *list.List) form
 	if argsList.Len() != 3 && argsList.Len() != 4 {
 		return newErrorFormulaArg(formulaErrorVALUE, fmt.Sprintf("%s requires 3 or 4 arguments", name))
 	}
-	args := list.New().Init()
-	settlement := argsList.Front().Value.(formulaArg).ToNumber()
-	if settlement.Type != ArgNumber {
-		args.PushBack(argsList.Front().Value.(formulaArg))
-		settlement = fn.DATEVALUE(args)
-		if settlement.Type != ArgNumber {
-			return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-		}
-	}
-	maturity := argsList.Front().Next().Value.(formulaArg).ToNumber()
-	if maturity.Type != ArgNumber {
-		args.Init()
-		args.PushBack(argsList.Front().Next().Value.(formulaArg))
-		maturity = fn.DATEVALUE(args)
-		if maturity.Type != ArgNumber {
-			return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-		}
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	if settlement.Number >= maturity.Number {
 		return newErrorFormulaArg(formulaErrorNUM, fmt.Sprintf("%s requires maturity > settlement", name))
 	}
@@ -10048,6 +9970,43 @@ func (fn *formulaFuncs) DDB(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(depreciation)
 }
 
+// prepareDataValueArgs convert first N arguments to data value for the
+// formula functions.
+func (fn *formulaFuncs) prepareDataValueArgs(n int, argsList *list.List) formulaArg {
+	l := list.New()
+	dataValues := []formulaArg{}
+	getDateValue := func(arg formulaArg, l *list.List) formulaArg {
+		switch arg.Type {
+		case ArgNumber:
+			break
+		case ArgString:
+			num := arg.ToNumber()
+			if num.Type == ArgNumber {
+				arg = num
+				break
+			}
+			l.Init()
+			l.PushBack(arg)
+			arg = fn.DATEVALUE(l)
+			if arg.Type == ArgError {
+				return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+			}
+		default:
+			return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+		}
+		return arg
+	}
+	for i, arg := 0, argsList.Front(); i < n; arg = arg.Next() {
+		dataValue := getDateValue(arg.Value.(formulaArg), l)
+		if dataValue.Type != ArgNumber {
+			return dataValue
+		}
+		dataValues = append(dataValues, dataValue)
+		i++
+	}
+	return newListFormulaArg(dataValues)
+}
+
 // DISC function calculates the Discount Rate for a security. The syntax of
 // the function is:
 //
@@ -10057,18 +10016,11 @@ func (fn *formulaFuncs) DISC(argsList *list.List) formulaArg {
 	if argsList.Len() != 4 && argsList.Len() != 5 {
 		return newErrorFormulaArg(formulaErrorVALUE, "DISC requires 4 or 5 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	if maturity.Number <= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, "DISC requires maturity > settlement")
 	}
@@ -10253,18 +10205,11 @@ func (fn *formulaFuncs) INTRATE(argsList *list.List) formulaArg {
 	if argsList.Len() != 4 && argsList.Len() != 5 {
 		return newErrorFormulaArg(formulaErrorVALUE, "INTRATE requires 4 or 5 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	if maturity.Number <= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, "INTRATE requires maturity > settlement")
 	}
@@ -10707,18 +10652,11 @@ func (fn *formulaFuncs) PRICEDISC(argsList *list.List) formulaArg {
 	if argsList.Len() != 4 && argsList.Len() != 5 {
 		return newErrorFormulaArg(formulaErrorVALUE, "PRICEDISC requires 4 or 5 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	if maturity.Number <= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, "PRICEDISC requires maturity > settlement")
 	}
@@ -10758,27 +10696,14 @@ func (fn *formulaFuncs) PRICEMAT(argsList *list.List) formulaArg {
 	if argsList.Len() != 5 && argsList.Len() != 6 {
 		return newErrorFormulaArg(formulaErrorVALUE, "PRICEMAT requires 5 or 6 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(3, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity, issue := args.List[0], args.List[1], args.List[2]
 	if settlement.Number >= maturity.Number {
 		return newErrorFormulaArg(formulaErrorNUM, "PRICEMAT requires maturity > settlement")
 	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Next().Value.(formulaArg))
-	issue := fn.DATEVALUE(args)
-	if issue.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
 	if issue.Number >= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, "PRICEMAT requires settlement > issue")
 	}
@@ -10938,18 +10863,11 @@ func (fn *formulaFuncs) RECEIVED(argsList *list.List) formulaArg {
 	if argsList.Len() > 5 {
 		return newErrorFormulaArg(formulaErrorVALUE, "RECEIVED allows at most 5 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	investment := argsList.Front().Next().Next().Value.(formulaArg).ToNumber()
 	if investment.Type != ArgNumber {
 		return investment
@@ -11061,18 +10979,11 @@ func (fn *formulaFuncs) TBILLEQ(argsList *list.List) formulaArg {
 	if argsList.Len() != 3 {
 		return newErrorFormulaArg(formulaErrorVALUE, "TBILLEQ requires 3 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	dsm := maturity.Number - settlement.Number
 	if dsm > 365 || maturity.Number <= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, formulaErrorNUM)
@@ -11096,18 +11007,11 @@ func (fn *formulaFuncs) TBILLPRICE(argsList *list.List) formulaArg {
 	if argsList.Len() != 3 {
 		return newErrorFormulaArg(formulaErrorVALUE, "TBILLPRICE requires 3 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	dsm := maturity.Number - settlement.Number
 	if dsm > 365 || maturity.Number <= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, formulaErrorNUM)
@@ -11131,18 +11035,11 @@ func (fn *formulaFuncs) TBILLYIELD(argsList *list.List) formulaArg {
 	if argsList.Len() != 3 {
 		return newErrorFormulaArg(formulaErrorVALUE, "TBILLYIELD requires 3 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	dsm := maturity.Number - settlement.Number
 	if dsm > 365 || maturity.Number <= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, formulaErrorNUM)
@@ -11231,18 +11128,11 @@ func (fn *formulaFuncs) YIELDDISC(argsList *list.List) formulaArg {
 	if argsList.Len() != 4 && argsList.Len() != 5 {
 		return newErrorFormulaArg(formulaErrorVALUE, "YIELDDISC requires 4 or 5 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
+	settlement, maturity := args.List[0], args.List[1]
 	pr := argsList.Front().Next().Next().Value.(formulaArg).ToNumber()
 	if pr.Type != ArgNumber {
 		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
@@ -11279,23 +11169,19 @@ func (fn *formulaFuncs) YIELDMAT(argsList *list.List) formulaArg {
 	if argsList.Len() != 5 && argsList.Len() != 6 {
 		return newErrorFormulaArg(formulaErrorVALUE, "YIELDMAT requires 5 or 6 arguments")
 	}
-	args := list.New().Init()
-	args.PushBack(argsList.Front().Value.(formulaArg))
-	settlement := fn.DATEVALUE(args)
-	if settlement.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+	args := fn.prepareDataValueArgs(2, argsList)
+	if args.Type != ArgList {
+		return args
 	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Value.(formulaArg))
-	maturity := fn.DATEVALUE(args)
-	if maturity.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
-	}
-	args.Init()
-	args.PushBack(argsList.Front().Next().Next().Value.(formulaArg))
-	issue := fn.DATEVALUE(args)
+	settlement, maturity := args.List[0], args.List[1]
+	arg := list.New().Init()
+	issue := argsList.Front().Next().Next().Value.(formulaArg).ToNumber()
 	if issue.Type != ArgNumber {
-		return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+		arg.PushBack(argsList.Front().Next().Next().Value.(formulaArg))
+		issue = fn.DATEVALUE(arg)
+		if issue.Type != ArgNumber {
+			return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE)
+		}
 	}
 	if issue.Number >= settlement.Number {
 		return newErrorFormulaArg(formulaErrorNUM, "YIELDMAT requires settlement > issue")
diff --git a/comment.go b/comment.go
index a89d2bb..07cd9f2 100644
--- a/comment.go
+++ b/comment.go
@@ -245,11 +245,11 @@ func (f *File) addDrawingVML(commentID int, drawingVML, cell string, lineCount,
 func (f *File) addComment(commentsXML, cell string, formatSet *formatComment) {
 	a := formatSet.Author
 	t := formatSet.Text
-	if len(a) > 255 {
-		a = a[0:255]
+	if len(a) > MaxFieldLength {
+		a = a[:MaxFieldLength]
 	}
 	if len(t) > 32512 {
-		t = t[0:32512]
+		t = t[:32512]
 	}
 	comments := f.commentsReader(commentsXML)
 	authorID := 0
diff --git a/datavalidation.go b/datavalidation.go
index 047a53c..80a0295 100644
--- a/datavalidation.go
+++ b/datavalidation.go
@@ -35,11 +35,6 @@ const (
 	DataValidationTypeWhole
 )
 
-const (
-	// dataValidationFormulaStrLen 255 characters
-	dataValidationFormulaStrLen = 255
-)
-
 // DataValidationErrorStyle defined the style of data validation error alert.
 type DataValidationErrorStyle int
 
@@ -120,7 +115,7 @@ func (dd *DataValidation) SetInput(title, msg string) {
 // SetDropList data validation list.
 func (dd *DataValidation) SetDropList(keys []string) error {
 	formula := strings.Join(keys, ",")
-	if dataValidationFormulaStrLen < len(utf16.Encode([]rune(formula))) {
+	if MaxFieldLength < len(utf16.Encode([]rune(formula))) {
 		return ErrDataValidationFormulaLenth
 	}
 	dd.Formula1 = fmt.Sprintf(`<formula1>"%s"</formula1>`, formulaEscaper.Replace(formula))
diff --git a/datavalidation_test.go b/datavalidation_test.go
index 5986375..c35693c 100644
--- a/datavalidation_test.go
+++ b/datavalidation_test.go
@@ -54,8 +54,8 @@ func TestDataValidation(t *testing.T) {
 	dvRange.Sqref = "A5:B6"
 	for _, listValid := range [][]string{
 		{"1", "2", "3"},
-		{strings.Repeat("&", 255)},
-		{strings.Repeat("\u4E00", 255)},
+		{strings.Repeat("&", MaxFieldLength)},
+		{strings.Repeat("\u4E00", MaxFieldLength)},
 		{strings.Repeat("\U0001F600", 100), strings.Repeat("\u4E01", 50), "<&>"},
 		{`A<`, `B>`, `C"`, "D\t", `E'`, `F`},
 	} {
diff --git a/errors.go b/errors.go
index 56a2280..f9eedde 100644
--- a/errors.go
+++ b/errors.go
@@ -51,6 +51,11 @@ func newInvalidStyleID(styleID int) error {
 	return fmt.Errorf("invalid style ID %d, negative values are not supported", styleID)
 }
 
+// newFieldLengthError defined the error message on receiving the field length overflow.
+func newFieldLengthError(name string) error {
+	return fmt.Errorf("field %s must be less or equal than 255 characters", name)
+}
+
 var (
 	// ErrStreamSetColWidth defined the error message on set column width in
 	// stream writing mode.
diff --git a/pivotTable.go b/pivotTable.go
index 6ce0173..270ee99 100644
--- a/pivotTable.go
+++ b/pivotTable.go
@@ -662,8 +662,8 @@ func (f *File) getPivotTableFieldsSubtotal(fields []PivotTableField) []string {
 func (f *File) getPivotTableFieldsName(fields []PivotTableField) []string {
 	field := make([]string, len(fields))
 	for idx, fld := range fields {
-		if len(fld.Name) > 255 {
-			field[idx] = fld.Name[0:255]
+		if len(fld.Name) > MaxFieldLength {
+			field[idx] = fld.Name[:MaxFieldLength]
 			continue
 		}
 		field[idx] = fld.Name
diff --git a/sheet.go b/sheet.go
index 43e277a..5738ced 100644
--- a/sheet.go
+++ b/sheet.go
@@ -27,6 +27,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"unicode/utf16"
 	"unicode/utf8"
 
 	"github.com/mohae/deepcopy"
@@ -1092,8 +1093,8 @@ func (f *File) SetHeaderFooter(sheet string, settings *FormatHeaderFooter) error
 	// Check 6 string type fields: OddHeader, OddFooter, EvenHeader, EvenFooter,
 	// FirstFooter, FirstHeader
 	for i := 4; i < v.NumField()-1; i++ {
-		if v.Field(i).Len() >= 255 {
-			return fmt.Errorf("field %s must be less than 255 characters", v.Type().Field(i).Name)
+		if len(utf16.Encode([]rune(v.Field(i).String()))) > MaxFieldLength {
+			return newFieldLengthError(v.Type().Field(i).Name)
 		}
 	}
 	ws.HeaderFooter = &xlsxHeaderFooter{
diff --git a/sheet_test.go b/sheet_test.go
index ef32d79..93a4ab6 100644
--- a/sheet_test.go
+++ b/sheet_test.go
@@ -217,10 +217,18 @@ func TestSetHeaderFooter(t *testing.T) {
 	assert.EqualError(t, f.SetHeaderFooter("SheetN", nil), "sheet SheetN is not exist")
 	// Test set header and footer with illegal setting.
 	assert.EqualError(t, f.SetHeaderFooter("Sheet1", &FormatHeaderFooter{
-		OddHeader: strings.Repeat("c", 256),
-	}), "field OddHeader must be less than 255 characters")
+		OddHeader: strings.Repeat("c", MaxFieldLength+1),
+	}), "field OddHeader must be less or equal than 255 characters")
 
 	assert.NoError(t, f.SetHeaderFooter("Sheet1", nil))
+	text := strings.Repeat("一", MaxFieldLength)
+	assert.NoError(t, f.SetHeaderFooter("Sheet1", &FormatHeaderFooter{
+		OddHeader:   text,
+		OddFooter:   text,
+		EvenHeader:  text,
+		EvenFooter:  text,
+		FirstHeader: text,
+	}))
 	assert.NoError(t, f.SetHeaderFooter("Sheet1", &FormatHeaderFooter{
 		DifferentFirst:   true,
 		DifferentOddEven: true,
diff --git a/styles_test.go b/styles_test.go
index a214aaa..9129914 100644
--- a/styles_test.go
+++ b/styles_test.go
@@ -262,10 +262,10 @@ func TestGetDefaultFont(t *testing.T) {
 
 func TestSetDefaultFont(t *testing.T) {
 	f := NewFile()
-	f.SetDefaultFont("Ariel")
+	f.SetDefaultFont("Arial")
 	styles := f.stylesReader()
 	s := f.GetDefaultFont()
-	assert.Equal(t, s, "Ariel", "Default font should change to Ariel")
+	assert.Equal(t, s, "Arial", "Default font should change to Arial")
 	assert.Equal(t, *styles.CellStyles.CellStyle[0].CustomBuiltIn, true)
 }
 
diff --git a/xmlDrawing.go b/xmlDrawing.go
index 0bb11ac..dabb34a 100644
--- a/xmlDrawing.go
+++ b/xmlDrawing.go
@@ -99,6 +99,7 @@ const (
 	MaxFontFamilyLength  = 31
 	MaxFontSize          = 409
 	MaxFileNameLength    = 207
+	MaxFieldLength       = 255
 	MaxColumnWidth       = 255
 	MaxRowHeight         = 409
 	TotalRows            = 1048576