The first real program I wrote was a forum in perl. But I didn't want to use "advanced" features like "use" (perl's word for importing a module). It just seemed too magical.

So, I had limited time manipulation capabilities. I tried to write all the date handling stuff by hand (with a lot of "if" statements for the special cases). I recall trying to make leap seconds work, but not sure if I actually did. It worked well enough for my purposes.

Also, no database, so I did it all with flat files. Worked better than you might expect (thanks to built-in flock()), but I wouldn't recommend it.