0.19.4 brings a lot of changes. See release notes here for more information.
There should be no downtime or very minimal downtime. If there are any issues, check the uptime site here or site status here
Local time can be seen here
Note: An update to postgres 16 and pictrs 0.5 is also comming soon, which will bring some downtime. Don’t know when yet, but will post an update, when I know.