Can't load site

Every now and then, I get the error that the site "can't be reached" because it took "too long to respond" as depicted in the attached screenshot on 10/7 around 1:40am EST.  My internet service provider is MCI Communications Services, Inc. d/b/a Verizon Business and IP address is 173.68.24.203.  Any ideas on how to resolve this and prevent it from recurring?
 

That is when we do daily backups and the records you may be accessing are not available.

Thanks!  Is there a public schedule of when the maintenance/back-ups are made for users to avoid accessing the site around then?  Posting this may also help manage expectations of members by reducing potential frustration and/or data loss during these times.

System maint every Sunday morning and backups anytime between midnight and 7 am Eastern.