diff --git a/Documentation/FunctionListByCategory.txt b/Documentation/FunctionListByCategory.txt
index b23d9a11..7ac726d3 100644
--- a/Documentation/FunctionListByCategory.txt
+++ b/Documentation/FunctionListByCategory.txt
@@ -39,7 +39,7 @@ CATEGORY_DATE_AND_TIME
 	TIMEVALUE               PHPExcel_Calculation_DateTime::TIMEVALUE
 	TODAY                   PHPExcel_Calculation_DateTime::DATENOW
 	WEEKDAY                 PHPExcel_Calculation_DateTime::DAYOFWEEK
-	WEEKNUM                 PHPExcel_Calculation_DateTime::WEEKOFYEAR
+	WEEKNUM                 PHPExcel_Calculation_DateTime::WEEKNUM
 	WORKDAY                 PHPExcel_Calculation_DateTime::WORKDAY
 	YEAR                    PHPExcel_Calculation_DateTime::YEAR
 	YEARFRAC                PHPExcel_Calculation_DateTime::YEARFRAC
diff --git a/Documentation/FunctionListByName.txt b/Documentation/FunctionListByName.txt
index 45a9daf7..2305f213 100644
--- a/Documentation/FunctionListByName.txt
+++ b/Documentation/FunctionListByName.txt
@@ -365,7 +365,7 @@ VERSION                 CATEGORY_INFORMATION            PHPExcel_Calculation_Fun
 VLOOKUP                 CATEGORY_LOOKUP_AND_REFERENCE   PHPExcel_Calculation_LookupRef::VLOOKUP
 
 WEEKDAY                 CATEGORY_DATE_AND_TIME          PHPExcel_Calculation_DateTime::DAYOFWEEK
-WEEKNUM                 CATEGORY_DATE_AND_TIME          PHPExcel_Calculation_DateTime::WEEKOFYEAR
+WEEKNUM                 CATEGORY_DATE_AND_TIME          PHPExcel_Calculation_DateTime::WEEKNUM
 WEIBULL                 CATEGORY_STATISTICAL            PHPExcel_Calculation_Statistical::WEIBULL
 WORKDAY                 CATEGORY_DATE_AND_TIME          PHPExcel_Calculation_DateTime::WORKDAY
 
diff --git a/Documentation/markdown/Functions/FunctionListByCategory.md b/Documentation/markdown/Functions/FunctionListByCategory.md
index 4ceb1e47..62c46f64 100644
--- a/Documentation/markdown/Functions/FunctionListByCategory.md
+++ b/Documentation/markdown/Functions/FunctionListByCategory.md
@@ -48,7 +48,7 @@
 	TIMEVALUE           | PHPExcel_Calculation_DateTime::TIMEVALUE
 	TODAY               | PHPExcel_Calculation_DateTime::DATENOW
 	WEEKDAY             | PHPExcel_Calculation_DateTime::DAYOFWEEK
-	WEEKNUM             | PHPExcel_Calculation_DateTime::WEEKOFYEAR
+	WEEKNUM             | PHPExcel_Calculation_DateTime::WEEKNUM
 	WORKDAY             | PHPExcel_Calculation_DateTime::WORKDAY
 	YEAR                | PHPExcel_Calculation_DateTime::YEAR
 	YEARFRAC            | PHPExcel_Calculation_DateTime::YEARFRAC
diff --git a/Documentation/markdown/Functions/FunctionListByName.md b/Documentation/markdown/Functions/FunctionListByName.md
index b69e4546..addae289 100644
--- a/Documentation/markdown/Functions/FunctionListByName.md
+++ b/Documentation/markdown/Functions/FunctionListByName.md
@@ -457,7 +457,7 @@
     Excel Function      | Category                       | PHPExcel Function
     --------------------|--------------------------------|-------------------------------------------
     WEEKDAY             | CATEGORY_DATE_AND_TIME         | PHPExcel_Calculation_DateTime::DAYOFWEEK
-    WEEKNUM             | CATEGORY_DATE_AND_TIME         | PHPExcel_Calculation_DateTime::WEEKOFYEAR
+    WEEKNUM             | CATEGORY_DATE_AND_TIME         | PHPExcel_Calculation_DateTime::WEEKNUM
     WEIBULL             | CATEGORY_STATISTICAL           | PHPExcel_Calculation_Statistical::WEIBULL
     WORKDAY             | CATEGORY_DATE_AND_TIME         | PHPExcel_Calculation_DateTime::WORKDAY
 
diff --git a/src/PhpSpreadsheet/Calculation.php b/src/PhpSpreadsheet/Calculation.php
index c60ce0c5..bd643dea 100644
--- a/src/PhpSpreadsheet/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation.php
@@ -1965,7 +1965,7 @@ class Calculation
         ],
         'WEEKNUM' => [
             'category' => Calculation\Categories::CATEGORY_DATE_AND_TIME,
-            'functionCall' => '\\PhpOffice\\PhpSpreadsheet\\Calculation\\DateTime::WEEKOFYEAR',
+            'functionCall' => '\\PhpOffice\\PhpSpreadsheet\\Calculation\\DateTime::WEEKNUM',
             'argumentCount' => '1,2',
         ],
         'WEIBULL' => [
diff --git a/src/PhpSpreadsheet/Calculation/DateTime.php b/src/PhpSpreadsheet/Calculation/DateTime.php
index 9f7d32f3..548e1f1d 100644
--- a/src/PhpSpreadsheet/Calculation/DateTime.php
+++ b/src/PhpSpreadsheet/Calculation/DateTime.php
@@ -1199,7 +1199,7 @@ class DateTime
     }
 
     /**
-     * WEEKOFYEAR
+     * WEEKNUM
      *
      * Returns the week of the year for a specified date.
      * The WEEKNUM function considers the week containing January 1 to be the first week of the year.
@@ -1218,7 +1218,7 @@ class DateTime
      *                                        2                Week begins on Monday.
      * @return    int        Week Number
      */
-    public static function WEEKOFYEAR($dateValue = 1, $method = 1)
+    public static function WEEKNUM($dateValue = 1, $method = 1)
     {
         $dateValue = Functions::flattenSingleValue($dateValue);
         $method = Functions::flattenSingleValue($method);
diff --git a/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php b/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
index d33a74ae..12c621f4 100644
--- a/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
@@ -145,7 +145,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array([DateTime::class, 'WEEKOFYEAR'], $args);
+        $result = call_user_func_array([DateTime::class, 'WEEKNUM'], $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }