Graph Panel to display exactly 1 day / last day

Hi, I want to display exactly 1 day (from 0:00am to 12:00pm) - Even though I have added relative time with "now-1d/d in the query options the graph panel is adding values from the new day as well, which means that the panel changes frequently instead of only once a day. I am new to Grafana, so please dont blame me for stupid questions :-))

Query I use: SELECT mean(“AutarkieProzent”) FROM “AC” WHERE timeFilter GROUP BY time(__interval) fill(null)
see screenshot added.

Query-1day