title: Using Cron for a weekly and monthly task
body: <p>Is there a crontab expression that will allow me to schedule a task to run weekly AND the first of each month? Of course, I could break these out into two separate lines:</p>
  
  <pre><code>15 3 * * 1,4 execute_task_weekly
  15 3 1 * * execute_task_monthly
  </code></pre>
  
  <p>But if the 1st of the month happens to coincide with Monday or Thursday, then it will kick off that task twice. I'm sure I could put some code into the script I'm running and then just tell cron to run daily, but I would prefer to do it in cron, if possible.</p>