Date/time handling code is pretty tricky - not leveraging what's in your platform is going to suck up a lot more time than you think. As for "databases rarely..." the answer to that is not to hand-roll your own wheel in PHP but to get a better database.
The article isn't "picking on" PHP, it's highlighting that timezone rules are constantly changing (which is not a language-specific problem) and details how to handle them (e.g. using an extension that's updated more frequently).