Site Crashed U_ILLEGAL_ARGUMENT_ERROR in IntlDateFormatter

Georgecy:

Hi Guys,
timezone-identifiers available from @lat instructions are listed at the end. The important for my case is Asia/Nicosia, Europe/Athens, which are available.( Running Joomla 4 system report, on same PHP, it shows also Europe/Nicosia and UTC as default timezone. Joomla has no problem with the PHP 8.1.1).

The actual timezone declared in php.ini is date.timezone = "Europe/Athens"

The Intl extension is also available.
I entered also in php.ini
[intl]
intl.default_locale = el_GR.UTF-8 which it had no effect on the issue.

Attached also screenshot From info.php

Asia/Aden, Asia/Almaty, Asia/Amman, Asia/Anadyr, Asia/Aqtau, Asia/Aqtobe, Asia/Ashgabat, Asia/Atyrau, Asia/Baghdad, Asia/Bahrain, Asia/Baku, Asia/Bangkok, Asia/Barnaul, Asia/Beirut, Asia/Bishkek, Asia/Brunei, Asia/Chita, Asia/Choibalsan, Asia/Colombo, Asia/Damascus, Asia/Dhaka, Asia/Dili, Asia/Dushanbe, Asia/Famagusta, Asia/Gaza, Asia/Hebron, Asia/Ho_Chi_Minh, Asia/Hong_Kong, Asia/Hovd, Asia/Irkutsk, Asia/Jakarta, Asia/Jayapura, Asia/Jerusalem, Asia/Kabul, Asia/Kamchatka, Asia/Karachi, Asia/Kathmandu, Asia/Khandyga, Asia/Kolkata, Asia/Krasnoyarsk, Asia/Kuala_Lumpur, Asia/Kuching, Asia/Kuwait, Asia/Macau, Asia/Magadan, Asia/Makassar, Asia/Manila, Asia/Muscat, Asia/Nicosia, Asia/Novokuznetsk, etc...., Europe/Amsterdam, Europe/Andorra, Europe/Astrakhan, Europe/Athens, Europe/Belgrade, etc....

It seems your PHP compilation is missing ICU timezone data.
Here is what I get (ICU TZData version):

In PHP there are two time zone objects, DateTimeZone that you tested with lat9 test and IntlTimeZone. Normally Intl DateFormatter can use both, but it is possible that when it is not explicitly written in code, default might be IntlTimeZone that uses ICU time zone data missing in your PHP.
This might be your problem, not 100% sure though.

You can try this code to test if ICU time zone data are here:

<?php
$zone_iter=IntlTimeZone::createEnumeration('GR'); // Create timezone iterator. To list one country time zones, use country code : 'Au', 'US', 'Fr', 'jp' ... For all countries, use NULL.
$zone_iter->rewind();
while($zone_iter->valid()){
    echo $zone_iter->current() . "\n";
   $zone_iter->next();
}
?>

You should get Europe/Athens if data are here, if not an error code or nothing.
You can replace 'GR' by 'CY' for Cyprus.

Hi Guys Thanks a lot for the support,
Finally I got today the requested PHP 8.1.28. With a note from the developer as follows

"It should solve all the PHP Intl extension issues you have experienced.
The problem was that for some obscure reasons, the Intl extension
shipping with all our packages were not able to read its localization
and timezone data despite it being available as a library."

After applying the @setlocale(LC_TIME, ['en_US', 'en_US.UTF-8', 'en-US']); in configures we are back in Business.
The developer recommended to use PHP8.2+ and I will test the latest version as soon as I receive it.

Now is it recomended to skip ZC 1.5.8 and upgrade straight to ZC 2.01 from ZC1.5.7d? Or is safer to go to 1.5.8a for more compatibility?

Thanks a lot again.

Now is it recomended to skip ZC 1.5.8 and upgrade straight to ZC 2.01 from ZC1.5.7d?

Yes.