I swear its like the majority of players who complain here NEVER look at the notices that pop up RIGHT ON THE LAUNCHER...
North American Data Center Maintenance (Mar. 14, Mar. 15)
At the following time, we will be performing maintenance on the North American data center. During this time, players may be temporarily unable to connect to the North American data center, or may become disconnected from the server, but gameplay will be possible by logging in again.

We apologize for any inconvenience this may cause and thank you for your understanding.

[Date & Time]
Mar. 14, 2015 9:00 p.m. to Mar. 15, 2015 3:00 a.m. (PDT)