Trying a simple code but failing

[hexemeister]

I am trying to make a simple example to work, but I have no success. PHP 5.3 It returns: Fatal error: Class 'ZipArchive' not found in /home/renato/dev/php/xlsx-teste/xlsxwriter.class.php on line 101

And some warnings: Warning: date_default_timezone_get(): It is not safe to rely on the system's timezone settings. You are required to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Sao_Paulo' for '-03/-3.0/no DST' instead in /home/renato/dev/php/xlsx-teste/xlsxwriter.class.php on line 33

Warning: date(): It is not safe to rely on the system's timezone settings. You are required to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Sao_Paulo' for '-03/-3.0/no DST' instead in /home/renato/dev/php/xlsx-teste/xlsxwriter.class.php on line 743 2024-06-20 12:51:40:Error: ZipArchive class does not exist

Sorry, but I am a newbie in PHP. Many thanks in advance.