title: Alert that will check every specific day of the month
body: <p>I have multiple Grafana dashboards with alerts defined and the alert query is checked every, for example, 24h. This is not a problem and everything is working well.</p>
  <p>I was wondering if there is any way to create an alert that will check every X day of the month. For example, every 12th of every month run the query and apply the alerting rules. Does anyone know if this is possible?</p>
  <p>Many thanks,
  Ricardo.</p>