Probably a two hour window to give me time to get things done. There may be an upgrade to lemmy 0.19.11 however that requires some modification of ZippyBot due to changes in the new version.
There will be downtime while the server is restarted, however hopefully this is brief.
Thanks
Demigodrick
The admins of the other instances could restore comments and posts from backup if it was deemed necessary.
Also things posted on the internet tend to live on