I have a log file with 2 columns: time|login Only from this information, I like to see the login behavior of particular users. These users are paid customers. Finding behavior patterns are not easy. Someone with experience can tell easily.

Awstats is fine, but not useful for me. Awstats is about the website traffic rather than details of individual activity.

So you want time parts? what kind? What's an example of a pattern an experienced person would find?

Either way, maybe start by parsing the time with on of the Date modules (i personally like Date::Calc once you have the date pieces). Depending on what you want, you could hash it up on hour, or hour range (e.g. early morning, morning, early afternoon, etc), or on day of week and see what the buckets look like.

Depending on your data, it might be very cool to convert the time to a epoch value and run some Fourier Transforms (FFT) against it and see what frequencies pop out.