Re: Local time zone

> This might work on some distrbutions, but not nearly on all. And > definitely not on Windows. On Debian it's not a symlink for example. It is still usable as one of the possibilities for the guessing algorithm to examine. Initially I also wanted to say that /usr/share/zoneinfo can be searched if /etc/localinfo is not a symbolic link, but I have just run a test: time { find /usr/share/zoneinfo -type f \ -exec cmp -s /etc/localtime '{}' \; -print; } and it took 1.5 seconds on openSUSE 11.4 and a second on Mac OS X 10.6 (by the way, on the latter /etc/localtime is a symbolic link). I suppose it would take less if I only examined paths corresponding to time zones known to PHP but it would likely still take a long time. Thus this is perhaps reasonable as optional behaviour (such as date_system_timezone_guess($try_harder=false) called with true as the argument) but certainly unwanted in code that executes by default. > It's a guess, and that's the problem. Guessing makes up for odd and > strange bugs if it's not 100% accurate (which it isn't). Which is why a pseudo-timezone called System is needed so that guesses do not have to be made. The extension would then convert /etc/localtime to its internal time zone description format or just use system-provided APIs as it used to do before PHP 5.1 if I understand correctly. > That's a really bad idea, as we've discussed before on this list. I can see why it is a bad idea to make such a time zone the default in a language used mostly for server-side software, although replacing it with a guess approximating such a time zone as the default, which is what PHP 5.1 did, seems even worse, and it is good to see that PHP 5.4 takes a better approach. However, I do not see how this is a bad idea for scripts people run among other software that all uses the system time zone--or perhaps I should even say 'the system's notion of local time', since (however uncommon this is) it might be different from any particular time zone. I have searched in the archive of php-internals and not found any discussion of this. Perhaps I am a bad searcher; I would appreciate if you pointed me at some of the past discussion. -- Oleg