Kibana version: 7.16 (SHA c5228354e5fdaf66f8466693f23f3d46d5632b88)

Elasticsearch version: 7.16

Server OS version: MacOS Big Sur 11.6

Browser version: Google Chrome Version 95.0.4638.69 (Official Build) (x86_64)

Browser OS version: MacOS Big Sur 11.6

Original install method (e.g. download page, yum, from source, etc.): I'm running Kibana from source, and connecting it to a 7.16-snapshot container from docker.elastic.co.

Describe the bug:

When adding a visualisation with relative dates, those were not converted to absolute dates.

As you can see in the GIF below, every time I refreshed the case, I was able to see more recent measurements because the end date was set as "now".

Additionally, the start_date also changes so that it's always X minutes ago, not at an absolute time.

Clicking "open visualisation" also displays the relative time as the chart's time range.

Steps to reproduce:

1. Access Observability > Uptime and go into the Exploratory View ("Analyze Data").
2. Add a series whose date rage is relative (i.e. 10 minutes ago to 1 minute ago)
3. Click "Add to Case" and add it to a case
4. Within the case to which you've added the visualisation, wait one minute or more, and refresh the page
5. You'll see that the time range is still relative on both ends of the graph (i.e. 10 minutes ago relative to current time, up to 1 minute ago relative to current time)
6. If you access the visualisation itself (three dots > Open Visualisation) you'll see that the time range there is relative too.

Expected behavior:

As per elastic/uptime#322, visualisations added to a case should have relative time ranges converted into absolute time ranges.

Screenshots (if relevant):

Errors in browser console (if relevant): No relevant errors.

Provide logs and/or server output (if relevant): No relevant errors.

Any additional context: I've found this while testing elastic/uptime#322.

Please let me know if the labels need changing.