If you just want a cron job that runs once a year by default, you can use hook_yearly().

<h3>Example</h3>
<pre>
// Easy-hook, uses rule: 0 0 1 1 *
function mymodule_yearly() {
  // Do some stuff
}
</pre>

P.S.: It's okay to laugh. The use case for this hook is very likely non-existent.