Add support for cells formatted as time (#224)

Cells formatted as "time" have values between 0 and 1. These values used to be considered as invalid.
Note: this uses what was started in #202

tests/Spout/Reader/XLSX/Helper/CellValueFormatterTest.php

@@ -18,8 +18,11 @@ class CellValueFormatterTest extends \PHPUnit_Framework_TestCase
             [CellValueFormatter::CELL_TYPE_NUMERIC, 42429, '2016-02-29 00:00:00'],
             [CellValueFormatter::CELL_TYPE_NUMERIC, '146098', '2299-12-31 00:00:00'],
             [CellValueFormatter::CELL_TYPE_NUMERIC, -700, null],
-            [CellValueFormatter::CELL_TYPE_NUMERIC, 0, null],
-            [CellValueFormatter::CELL_TYPE_NUMERIC, 0.5, null],
+            [CellValueFormatter::CELL_TYPE_NUMERIC, 0, '1900-01-01 00:00:00'],
+            [CellValueFormatter::CELL_TYPE_NUMERIC, 0.25, '1900-01-01 06:00:00'],
+            [CellValueFormatter::CELL_TYPE_NUMERIC, 0.5, '1900-01-01 12:00:00'],
+            [CellValueFormatter::CELL_TYPE_NUMERIC, 0.75, '1900-01-01 18:00:00'],
+            [CellValueFormatter::CELL_TYPE_NUMERIC, 0.99999, '1900-01-01 23:59:59'],
             [CellValueFormatter::CELL_TYPE_NUMERIC, 1, '1900-01-01 00:00:00'],
             [CellValueFormatter::CELL_TYPE_NUMERIC, 59.999988425926, '1900-02-28 23:59:59'],
             [CellValueFormatter::CELL_TYPE_NUMERIC, 60.458333333333, '1900-02-28 11:00:00'],

tests/Spout/Reader/XLSX/ReaderTest.php

@@ -181,6 +181,28 @@ class ReaderTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedRows, $allRows);
     }
 
+    /**
+     * @return void
+     */
+    public function testReadShouldSupportDifferentTimesAsNumericTimestamp()
+    {
+        // make sure dates are always created with the same timezone
+        date_default_timezone_set('UTC');
+
+        $allRows = $this->getAllRowsForFile('sheet_with_different_numeric_value_times.xlsx');
+
+        $expectedRows = [
+            [
+                \DateTime::createFromFormat('Y-m-d H:i:s', '1900-01-01 00:00:00'),
+                \DateTime::createFromFormat('Y-m-d H:i:s', '1900-01-01 11:29:00'),
+                \DateTime::createFromFormat('Y-m-d H:i:s', '1900-01-01 23:29:00'),
+                \DateTime::createFromFormat('Y-m-d H:i:s', '1900-01-01 01:42:25'),
+                \DateTime::createFromFormat('Y-m-d H:i:s', '1900-01-01 13:42:25'),
+            ]
+        ];
+        $this->assertEquals($expectedRows, $allRows);
+    }
+
     /**
      * @return void
      */