There is a number of very good, but not very well known Perl modules on CPAN.

Sometimes I'll be writing short posts about such modules which I use and appreciate.

When you are dealing with date and time in Perl, inevitably you will reach a point when you need to do more than is immediately available through Perl builtins and the POSIX module.

Then you try to find a module for what you want on CPAN, and you drown in literally hundreds of modules dealing with dates and times.

Luckily, there is a clear winner in this "modules war" - everybody (or at least everybody sane) recommends to use the DateTime module, and for the things that it cannot do, various other modules from the same namespace.

So life is bright for a perl programmer on the date/time front, until you have a need to parse a date represented in one of a multitude of "human-readable" formats, and you don't know in advance which one it is going to be.

The DateTime itself cleverly refuses to deal with this task at all, and instead recommends to use one of the DateTime::Format:: modules.

You will be relieved to know that you can easily and quickly create parsers for your own date formats - that is, if you are able to remember that you should use the module aptly named DateTime::Format::Builder::Parser::Regex.

The documentation for DateTime::Format::Bork is also very enlightening.


I prefer to go against the flow here, and use a module somewhat unfortunately named Time::ParseDate. I mean, it could just as easily be Date::ParseTime or something, right? Worse, for years I had trouble remembering what distribution this modules comes from (it, very obviously for everyone but me, can be found in the Time-modules distribution).

At any rate, if we forget for a second about the funny names, this module is truly a wonder:

$ perl -MTime::ParseDate -le 'print parsedate("Sat Feb 14 00:31:30 2009")'
$ perl -MTime::ParseDate -le 'print parsedate("2 days ago")'
$ perl -MTime::ParseDate -le 'print parsedate("18:30")'

It exports a single function, which takes a single parameter (unless you want to specify some options which are rarely needed in practice), and you get your epoch seconds back in return. Very simple, very elegant, gets the job done. I wish there were more "straight to the point" modules like this one.