$format = $this->MoodleExcelFormat2PearExcelFormat($format);
/// Convert the date to Excel format
$timezone = get_user_timezone_offset();
- $value = ((usertime($date) + (int)($timezone * HOURSECS * 2)) / 86400) + 25569;
+ if ($timezone == 99) {
+ // system timezone offset in seconds
+ $offset = (int)date('Z');
+ } else {
+ $offset = (int)($timezone * HOURSECS * 2);
+ }
+ $value = ((usertime($date) + $offset) / 86400) + 25569;
/// Add the date safely to the PEAR Worksheet
$this->pear_excel_worksheet->writeNumber($row, $col, $value, $format);
}