On the 25th Feb my ISP will be doing some work on their network core.
This will give 1-2 hours of downtime in the afternoon/evening.
We're also getting a replacement static IP address (bit of a shock as we've had the old one for years), so sometime within 30 days of the 25th I will also need to reconfigure the router for the new IP, which will lead to additional downtime.
At the point of the new IP coming into action, we will need to update all of this domain's DNS A records to point to the new IP. This will take a period of up to 24 hours for worldwide nameserver propagation, therefore the site may be unavailable for up to 24 hours when this takes place.
We may also need to get our reverse-DNS entry updated after the IP change for mail to work to all mailservers, so mail notification from the site may also be affected. (Not everyone's e-mail, it's just that some picky mailservers like hotmail expect a valid reverse DNS entry in order to accept delivery of e-mail).
So in summary: down for a couple of hours on the 25th, then some time within 30 days after that the site may be inaccessible for up to 24 hours. I'll post updates on VOD if necessary.