I was just going to post an announcement on the forums regarding this.
We currently don't send emails for maintenances but you can subscribe to
the RSS feed (you'll have to filter LCCS maintenances since currently we
have one single feed for Acrobat.com and LCCS).
The maintenance windows is Thursdays 5pm-7pm, but of course we don't have
deployment every Thursday and most of the times we have no scheduled
downtime.
For this deployment we WILL have scheduled downtime (we need to upgrade a
central component of the system) but we'll keep it as short as possible
(we'll get everything ready and then do a full cluster shutdown and
restart. Again, we try to minimize downtime as much as possible but some
times we cannot avoid it.
I think "by contract" we give at least 48 hours notice for maintenances
but we'll do our best to announce "service disruption" as much in advance
as possible.
Sorry for the inconvenience, and as I said, we'll try to limit the
downtime to as little as possible.