one other idea was to connect the data point of unfinished period with a dashed/interrupted line

but this approach would be much more "costly" to make it good looking and compatible at all places where graphs are used/shown...

so no connection at all should be fine :-)

another example:

a possible second step:
maybe one can show even an estimated forecast, e.g. like this?

@mattab would be nice to tackle this one at some point as it's always "irritating" for unfinished periods. Maybe there is a way to show the last dot and last line in a light red or something. On hover it could say the day is not yet finished but not sure how complicated it is to implement. Would be useful especially since we want to show more of such graphs.

This would be great, also at the top dashboard where the data of the unfinished day is compared to the completed day.

Added Major tag and moved into 3.0.0 milestone so we keep an eye on this important issue 👍

see also #6784

Before working on this need to clarify with @mattab how to solve this problem. Related also #6784 which may need similar solution.

In an ideal world, we would maybe show the forecast line, but this could make the whole issue a lot more complex and time consuming.
So instead maybe we could first start by putting the last section of the line graph into a dash line, indicating to the user that there is something special about this last data point? That might be good enough to remove the "shock" of seeing the data point way down.

That might actually now be easy as our chart libs don't support different looks for the same chart line. Not sure if adding a separat chart line for the last point only would work easily though.

@tsteur Was there a new issue created for implementing this in ImageGraph also (as discussed in #18086), or shall we keep this one open for that?

created #18169 . I wouldn't have created one and just waited until someone creates it as we likely won't work on it anytime soon anyway.