Interesting title considering he never mentions why using DateTime math is difficult. I personally have never had to schedule jobs with PHP, but I also don’t write PHP services (or daemons, or what ever).
The subtitle is a take off on the fact that a few years ago (ok, maybe more than a few now) there was a talking Barbie that had as one of it’s saying “Math is hard”. It was roundly ridiculed in tech communities. In the PHP community, it somehow morphed into “DateTime Math is hard”.
Having used several languages, DateTime math is no harder in PHP than it is in other languages. It is easier in PHP than some of the other languages I’ve used thanks to Derick Rethan’s great DateTime extension that handles a lot of the complexities. None the less, DateTime math is my personal nemesis. In any given program, if I screw something up, it’s usually DateTime math. :)
Hope that clears things up. :)