I rember asking this in c4 also but whatver i never learn:
When is the server planned up and running in GMT or GMT+1 time if you will? Whats the difference cdt and gmt ?
"CDT" is "Central Daylight Time" - UTC-0500 ("UTC" is the universal world time every time zone on Earth is based on, and differs from the older GMT by up to 0.9 seconds).
This means the downtime is scheduled from 13:00 UTC to 19:00 UTC.
For the inhabitants of Iceland, the local time is the same as the UTC time. Inhabitants from some parts of western Europe, like Portugal, Great Britain and Ireland, have to add an hour to those time - for them the downtime occurs between 14:00 and 20:00. For those of us living in the rest of the central and western Europe, this means the downtime will occur between 15:00 and 21:00 our time zone (MEST), for those further east in Europe - like Greece or Ukraine - it'll be between 16:00 and 22:00 (time zone: EEST), and for those even further east, in the Moscow time zone, it'll last between 17:00 and 23:00.
New York is currently at UTC-04:00 (don't ask me about the time zone name, I usually just remember the numerical values ... :)). This means the downtime - 13:00 UTC to 19:00 UTC - lasts between 09:00 and 15:00 New York time.