Estimatingly how long is the server shutdown before I can start updating?

On 02/25/15, starting at 01:30 PST, ranked queues will be disabled in preparation for patch 5.4. At 03:00 PST, the servers will be shut down and all games currently in progress will end in a draw and stats will not be recorded. We estimate the battlegrounds will be unavailable for 6 hours.

What do they mean by battlegrounds? Normal games will be down for 6 hours too? Or just ranked? If both then I guess I should sleep