partly support time cell

col.go

@@ -41,6 +41,17 @@ type XfRk struct {
 	Rk    RK
 }
 
+func (xf *XfRk) String(wb *WorkBook) string {
+	switch wb.Xfs[21].formatNo() {
+	case 27:
+		if f, e := xf.Rk.Float(); e == nil {
+			t := TimeFromExcelTime(f, true)
+			return t.Format("2006.01") //TODO it should be international
+		}
+	}
+	return fmt.Sprintf("%s", xf.Rk.String())
+}
+
 type RK uint32
 
 func (rk RK) String() string {
@@ -58,6 +69,23 @@ func (rk RK) String() string {
 	}
 }
 
+var ErrIsInt = fmt.Errorf("is int")
+
+func (rk RK) Float() (float64, error) {
+	multiplied := rk & 1
+	isInt := rk & 2
+	val := rk >> 2
+	if isInt == 0 {
+		f := math.Float64frombits(uint64(val) << 34)
+		if multiplied != 0 {
+			f = f / 100
+		}
+		return f, nil
+	} else {
+		return 0.0, ErrIsInt
+	}
+}
+
 type MulrkCol struct {
 	Col
 	Xfrks    []XfRk
@@ -72,7 +100,7 @@ func (c *MulrkCol) String(wb *WorkBook) []string {
 	var res = make([]string, len(c.Xfrks))
 	for i := 0; i < len(c.Xfrks); i++ {
 		xfrk := c.Xfrks[i]
-		res[i] = xfrk.Rk.String()
+		res[i] = xfrk.String(wb)
 	}
 	return res
 }