If you're not going to use a module, the best knob is to use functions that are compatible with each other (i.e., use functions that assume UTC only or the local time zone only, and don't mix them).

But the better knob would be to not worry about it at all. Instead, use one of the Date::* modules from CPAN to do all the grunt work.

Update: By the way, I think you wanted to use <code> tags for (your question) your question, rather than <center>. You might go back to your node and fix it...

...roboticus

Update: The [node] in parenthesis is present only so that node "id vs. node oddity" makes sense.