At YAPC::Europe 2013 I gave a talk about API design principles, illustrated using DateTime as an example of a popular module that causes pain by bad design. In places I contrasted it with the much better design of the new time library being standardised in the Java world, known as JSR-310 <http://download.java.net/jdk8/docs/api/java/time/package-summary.html>. One of the questions I got at the end of the talk was what we should use instead of DateTime, and I answered that we don't have well-designed modules covering all of its jobs, and I'd rather like to see someone implement JSR-310 for Perl.
If anyone is motivated to port JSR-310, please mention it on this mailing list, to avoid duplication of effort and so on. Note that there's a public reference implementation, under the BSD licence. It'd probably also be worth communicating with Stephen Colebourne, the lead on the JSR-310 project, for insight into the design. -zefram
