函数 date_default_timezone_set() 不可用

Question

As the title says, can anybody explain why the code

ini_set( 'date.timezone', 'Europe/Athens' );

works but

date_default_timezone_set( 'Europe/Athens' );

does not? It gives me this error:

Fatal error: Call to undefined function date_default_timezone_set()

I was looking for a solution to convert a timestamp and all I could find on the web was to use date_default_timezone_set . But the conversion had always 1 hour difference.

Then I found this topic " strftime() function showing incorrect time " which is using the init_set code (and afterwards I've RTM and found out that it's already mentioned in the documentation). I tried it and it worked.

But I haven't found an answer why date_default_timezone_set is not working.

Can anybody explain please?

Answer 1

You must be using an old version of PHP.

date_default_timezone_set is for PHP 5.1.2 and above.

Try php -v and check your PHP version.

Answer 2

您可以使用：

putenv("TZ=Europe/Berlin"); // PHP 4

Answer 3

localhost

server

It's quite late, I got the same issue and I see there is the difference, I post the screenshot from my localhost and my personal server phpinfo for the timezone.

On my localhost, date_default_timezone_set('[timezone]') works correctly, however, on the server, it always return the UTC. Based on the php doc, it looks like the timezone is not set in the php ini of my server, so i likely ignored the the timezone set since no value is defined previously.

Using the init_set, it makes the timezone to be available. I think the timezone is not predefined on the php ini is the cause.