The servers will be down for five hours, which is pretty reasonable for a full update.
Here are the local time conversions for you:
The short official blurb from Funcom:
The servers will come down for “Issue #2 – Digging Deeper” on September 18th at 11:00 GMT / 7am EDT / 4am PDT (check this link to see when this is in your timezone). The downtime is scheduled to last 5 hours.
Don’t forget you can check out the preview vid of the new content right here.
Over to you: are you excited for the new content?