Infrastructure maintenance events don't have a set interval between occurrences.
But generally, happen once every two weeks and take not more than 3-5 minutes to be completed.
Naturally, our intent is to minimize downtime as much as possible.
So often than not, this happens without it impacting your workload.
Moreover, you will be notified before this process is initiated.
You can subscribe to alerts at https://status.webhostingmagic.com
