Graphs show data of of "unfinished periods" and "complete periods" in same way.*

Since imho comparison of data of "unfinished periods" with "complete periods" does not make big sense, there should be visiualization for the difference to trigger people to be aware of this problem
One idea is not connecting the data point of "unfinished period" to the others before even this period is finished.
This may look like this:

*why are there unfinished periods?
When comparing data e.g. number of visits, entry pages etc
with data of day before there is a problem:
when checking earlier than 23:59
there is always a difference because
the period taken into account is shorter
than the complete day before
and with this not all "things" of this day has already happened.

An example:
Looking at data at 9:00 in the morning:
actual data is taken from 0:00 to 9:00 = 9h
the data for comparison form 0:00 to 0:00 = 24h

This issue is an extract of
"comparison of data of "unfinished periods" with "complete periods" does not make big sense e.g. in widget" #10282
which addresses problem in general for data shown in table and in graphs