Yes, some sort of maintenance is happening, but on a Friday night this has to be an unscheduled so I am assuming something failed or is failing...possibly a server, but in all the years I've done IT a notice was sent to users advising that the site would be down for schedule maintenance Time/Date/Duration...so again this is likely unscheduled. Maybe this is the only time they can do this to, but in that event you would think something would have been said to users...even if this is a site enhancement. Who knows...