The homepage, forum, wiki and IRC will be going offline for about five minutes on 2018-01-13, between 10:00 and 10:15 UTC.
For convenience, this means:
EST (USA east coast):
2018-01-13, 05:00-05:15
UTC (UK):
2018-01-13, 10:00-10:15
CET (Most of Europe):
2018-01-13, 11:00-11:15
AEDT (Australia east coast):
2018-01-13, 21:00-21:15
The intent is to install security updates on the server which hosts the homepage, forum, wiki and IRC. These will be non-disruptive to functionality, as the server is running a stable OS release that gets critical fixes only.