The Pokémon Global Link announced that they are changing the Weekly Maintenance Time for the system. This is the normally scheduled downtime and not the
extended maintenance that sometimes takes place.
Change in Scheduled Weekly Maintenance Time
Starting on Tuesday, August 5, 2014, the scheduled weekly maintenance time for the Pokémon Global Link will change as follows:
Current:
US: Every Monday from 3:00 p.m. until 7:00 p.m. EST
UK: Every Monday from 9:00 p.m. until Tuesday at 1:00 a.m. BST
New:
US: Every Monday from 8:00 p.m. until midnight EST
UK: Every Tuesday from 1:00 a.m. until 5:00 a.m. BST
This will also affect the time that new Rating Battle seasons begin.
Source:
http://3ds.pokemon-gl.com/information/53bb11c1-3a44-4563-88d8-0204076ee8a2