Planned Server Outage

Our ISP is upgrading us to a new server; a server that is both faster and more reliable.
Migration of our website to the new server will begin later this week. The process requires the server to be rebooted twice; once during the migration and again 48-72 hours after the migration is complete. Please expect 15-20 minutes of downtime between 10 p.m. and 4 a.m. Mountain Time while the server reboots.
 
They of course didn't tell me exactly what days.