Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/TimeZone.php
public static function setTimeZone($timezone)
    {
        if (self::validateTimezone($timezone)) {
            self::$timezone = $timezone;

            return true;
        }

        return false;
    }
public static function setTimeZone($timezone)
    {
        if (self::validateTimezone($timezone)) {
            self::$timezone = $timezone;

            return true;
        }

        return false;
    }
public static function setTimeZone ( $ timezone ) { if ( self :: validateTimezone ( $ timezone ) ) { self :: $ timezone = $ timezone ; return true ; } return false ; }
Set the Default Timezone used for date/time conversions.

@param string $timezone Time zone (e.g. 'Europe/London')

@return bool Success or failure
Set the Default Timezone used for date / time conversions .