dateinterval

I need a regular expression to validate durations in the ISO 8601 duration format (with the exception of fractional parts which I don't need). PnYnMnDTnHnMnS PnW Here is what I have: ^P(\d+Y)?(\d+M)?(\d+W)?(\d+D)?(T(\d+H)?(\d+M)?(\d+S)?)?$ The only problem is that the strings P and PT are allowed with this regex as all of the parts are "zero or one" ? . There needs to be at least one component (date or time) If there is a T then there needs to be a time component (H, M, or S) If there is a T then there may or may not be any date components (Y, M, or D) Overflow is allowed (e.g. P72H is mostly

There are plenty of questions asking how to do this the other way (converting from this format), but I cant find anything on how to output in the ISO 8601 duration format in PHP. So I have a heap of duration strings in human readable format - I want to convert them into the ISO 8601 format on the fly to print the durations for HTML5 microdata. Below is a sample of some of the strings coming in, and how they should be formatted "1 hour 30 minutes" --> PT1H30M "5 minutes" --> PT5M "2 hours" --> PT2H You get the idea. I can push the string into an interval object in PHP: date_interval_create_from

I failed to find a proper solution to this issue. As you see in Example #3 in the PHP documentation, they state that one must beware when adding months using the DateInterval in DateTime::add. There's not really any explanation for why the method's behavior is as such and what I can do to avoid this, which I find to be an error at first sight. Anyone have some insight into this? The issue is that each month can have a different number of days in them. The question is what you're doing when you want to increment a date by 1 month. Per the PHP documentation if you're on January 31st (or 30th)

I discovered that a DateTime object in PHP can be compared to another as the ">" and "<" operators are overloaded. Is it the same with DateInterval? As I was trying to answer this question, I found something strange: <?php $today = new DateTime(); $release = new DateTime('14-02-2012'); $building_time = new DateInterval('P15D'); var_dump($today->diff($release)); var_dump($building_time); var_dump($today->diff($release)>$building_time); var_dump($today->diff($release)<$building_time); if($today->diff($release) < $building_time){ echo 'oK'; }else{ echo 'Just a test'; } It always echoes "Just a