/**
* Convert a date from Excel to PHP
*
* @param integer $dateValue Excel date/time value
* @param boolean $adjustToTimezone Flag indicating whether $dateValue should be treated as
* a UST timestamp, or adjusted to UST
* @param string $timezone The timezone for finding the adjustment from UST
* @return integer PHP serialized date/time
*/
public static function excelToPHP($dateValue = 0, $adjustToTimezone = false, $timezone = null)
{
if (self::$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 = (int) $returnValue;
}
} else {
$hours = round($dateValue * 24);
$mins = round($dateValue * 1440) - round($hours * 60);
$secs = round($dateValue * 86400) - round($hours * 3600) - round($mins * 60);
$returnValue = (int) gmmktime($hours, $mins, $secs);
}
$timezoneAdjustment = $adjustToTimezone ? TimeZone::getTimezoneAdjustment($timezone, $returnValue) : 0;
return $returnValue + $timezoneAdjustment;
}
