时间格式PT00H00M00S的名称是什么？使用什么语言？

I'm working with excel documents using PHP scripts and cannot determine what data type/format PT00H00M00S is, and subsequently I can't find a way to work with it without using regex. I'd like to convert this into a more standard time format (00:00:00) and I can't research this on google because I don't know what "PT...S" is actually called as a date type/format.I'm working with excel documents using PHP scri