From caad6b1956b6b407baa3a2d0cca0caf5e2d09bfa Mon Sep 17 00:00:00 2001
From: MarkBaker <mark@lange.demon.co.uk>
Date: Sat, 28 Mar 2015 17:45:49 +0000
Subject: [PATCH] Minor bugfixes for date/time edge cases

---
 Classes/PHPExcel/Calculation/DateTime.php | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/Classes/PHPExcel/Calculation/DateTime.php b/Classes/PHPExcel/Calculation/DateTime.php
index 6eb96fd2..56c14079 100644
--- a/Classes/PHPExcel/Calculation/DateTime.php
+++ b/Classes/PHPExcel/Calculation/DateTime.php
@@ -1071,7 +1071,9 @@ class PHPExcel_Calculation_DateTime {
 	public static function DAYOFMONTH($dateValue = 1) {
 		$dateValue	= PHPExcel_Calculation_Functions::flattenSingleValue($dateValue);
 
-		if (is_string($dateValue = self::_getDateValue($dateValue))) {
+		if ($dateValue === null) {
+            $dateValue = 1;
+		} elseif (is_string($dateValue = self::_getDateValue($dateValue))) {
 			return PHPExcel_Calculation_Functions::VALUE();
 		} elseif ($dateValue == 0.0) {
 			return 0;
@@ -1114,7 +1116,9 @@ class PHPExcel_Calculation_DateTime {
 		}
 		$style = floor($style);
 
-		if (is_string($dateValue = self::_getDateValue($dateValue))) {
+		if ($dateValue === null) {
+            $dateValue = 1;
+		} elseif (is_string($dateValue = self::_getDateValue($dateValue))) {
 			return PHPExcel_Calculation_Functions::VALUE();
 		} elseif ($dateValue < 0.0) {
 			return PHPExcel_Calculation_Functions::NaN();
@@ -1180,7 +1184,9 @@ class PHPExcel_Calculation_DateTime {
 		}
 		$method = floor($method);
 
-		if (is_string($dateValue = self::_getDateValue($dateValue))) {
+		if ($dateValue === null) {
+            $dateValue = 1;
+		} elseif (is_string($dateValue = self::_getDateValue($dateValue))) {
 			return PHPExcel_Calculation_Functions::VALUE();
 		} elseif ($dateValue < 0.0) {
 			return PHPExcel_Calculation_Functions::NaN();
@@ -1216,7 +1222,9 @@ class PHPExcel_Calculation_DateTime {
 	public static function MONTHOFYEAR($dateValue = 1) {
 		$dateValue	= PHPExcel_Calculation_Functions::flattenSingleValue($dateValue);
 
-		if (is_string($dateValue = self::_getDateValue($dateValue))) {
+		if ($dateValue === null) {
+            $dateValue = 1;
+		} elseif (is_string($dateValue = self::_getDateValue($dateValue))) {
 			return PHPExcel_Calculation_Functions::VALUE();
 		} elseif ($dateValue < 0.0) {
 			return PHPExcel_Calculation_Functions::NaN();
@@ -1245,7 +1253,9 @@ class PHPExcel_Calculation_DateTime {
 	public static function YEAR($dateValue = 1) {
 		$dateValue	= PHPExcel_Calculation_Functions::flattenSingleValue($dateValue);
 
-		if (is_string($dateValue = self::_getDateValue($dateValue))) {
+		if ($dateValue === null) {
+            $dateValue = 1;
+		} elseif (is_string($dateValue = self::_getDateValue($dateValue))) {
 			return PHPExcel_Calculation_Functions::VALUE();
 		} elseif ($dateValue < 0.0) {
 			return PHPExcel_Calculation_Functions::NaN();