Either of the above mentioned ways will work.. however, I would recommend using the Date::Calc method for one main reason: It's not dependant on the number of bits that the underlying machine uses to store its dates in. Both will work the same way for dates between the years 1901 and 2038 (roughly), but beyond that range, localtime will return incorrect values on 32 bit systems (which all x86 machines still are). I don't know if this will be an issue for you, but it's a good thing to know.

On a minor issue, you might also prefer Date::Calc because it lets you specify dates in a more intuitive way than Time::Local, which makes you subtract 1 from the month, since it's 0 based, and subtract 1900 from the year (I believe).