Please, for the love of everything anyone has ever held dear, the US is on Daylight Savings time now, ergo xDT.
Eastern Daylight Time. - EDT
Central Daylight Time. - CDT
Mountain Daylight Time. - MDT
Pacific Daylight Time. - PDT
That covers the continental US time zones from east (where that big ball of light comes up) to the west (where it goes down) and they are each 1 successive hour apart.
22:00 would be the 22nd hour of a day. A 'day' begins at midnight, right? Right. You've stared at the game clock and noticed that the day changes one game minute after 23:59 right? Right. Same thing. 24-hour time has no AM or PM. If you see a time referenced as anything more than 12 hours, subtract 12 from it and that's your time in Post Meridiem or PM. Otherwise it's AM.
So if you REALLY want to know what time maintenance will now end in CST, even though we're not on Standard Time right now, that would be 11pm or 23:00 CST.
It's not that damned difficult. /sigh
On the server front, I can only assume character data is stored in some form of SQL environment which would take a good amount of time to transfer millions upon millions of rows of character data from one database to another. Not only would new rows be added to a destination DB, but name checks would have to flag new additions if there's a conflict. While that process would be completely automated in a lengthy SQL script, it would still take hours to run with the sheer amount of data I'd expect. One hiccup and the script borks, the whole thing gets to be re-run. But this is why they stopped character transfers early, so they could test the server merges with a consistent data set.
Still, I'd love just 10 minutes with the system to see how its structured... maybe 10 more minutes to make a few small modifications.