I'm having problems setting a cache expiration date for the wiki.

I have this code on LocalSettings.php:

$cache_seconds = 30; // Duration of the page cache in seconds $cache_date = gmdate("YmdHis", mktime() - $cache_seconds); $wgCacheEpoch = max($wgCacheEpoch, $cache_date);

Notice that I changed the format from the default "M d Y H:i:s" so it is consistent with the format specified in the MediaWiki help.

That should keep pages on cache for 30 seconds. But the cache expires immediately.

Is this a correct way to configure cache expiration?

Is there any timezone configuration that could be affecting this?

Thanks for any help you can give me.