Convert the FULL Excel date serial format to Unix timestamp

Question

I\'ve seen lots of references to converting the \"date\" portion of the Excel serial date format, but everyone seems to skip the \"time\" portion of it.

Here is what

Answer 1

You clearly haven't looked very hard:

Taken directly from the PHPExcel Date handling code:

public static function ExcelToPHP($dateValue = 0) {
    if (self::$ExcelBaseDate == self::CALENDAR_WINDOWS_1900) {
        $myExcelBaseDate = 25569;
        //    Adjust for the spurious 29-Feb-1900 (Day 60)
        if ($dateValue < 60) {
            --$myExcelBaseDate;
        }
    } else {
        $myExcelBaseDate = 24107;
    }

    // Perform conversion
    if ($dateValue >= 1) {
        $utcDays = $dateValue - $myExcelBaseDate;
        $returnValue = round($utcDays * 86400);
        if (($returnValue <= PHP_INT_MAX) && ($returnValue >= -PHP_INT_MAX)) {
            $returnValue = (integer) $returnValue;
        }
    } else {
        $hours = round($dateValue * 24);
        $mins = round($dateValue * 1440) - round($hours * 60);
        $secs = round($dateValue * 86400) - round($hours * 3600) - round($mins * 60);
        $returnValue = (integer) gmmktime($hours, $mins, $secs);
    }

    // Return
    return $returnValue;
}    //    function ExcelToPHP()

Set self::$ExcelBaseDate == self::CALENDAR_WINDOWS_1900 as necessary to indicate the Excel base calendar that you're using: Windows 1900 or Mac 1904

and if you want a PHP DateTime object instead:

public static function ExcelToPHPObject($dateValue = 0) {
    $dateTime = self::ExcelToPHP($dateValue);
    $days = floor($dateTime / 86400);
    $time = round((($dateTime / 86400) - $days) * 86400);
    $hours = round($time / 3600);
    $minutes = round($time / 60) - ($hours * 60);
    $seconds = round($time) - ($hours * 3600) - ($minutes * 60);

    $dateObj = date_create('1-Jan-1970+'.$days.' days');
    $dateObj->setTime($hours,$minutes,$seconds);

    return $dateObj;
}    //    function ExcelToPHPObject()