24h derivate/group starting time

I have setup a bar graph that gives me total data transferred over 24 h like this:

SELECT non_negative_derivative(max(“bytes_recv”), 24h) FROM “net” WHERE (“interface” = ‘mvneta0.4090’) AND $timeFilter GROUP BY time(24h) fill(null)

This is to sum the total transferred amount from a pfsense counter. However, this seems to aggregate from 01:00 to 01:00 the next day, not 00:00. I suspect this has to do with timezone (since I’m in CET +1), but can I tell the query to skew the window with a 1h offset, or is this caused by InfluxDB?

I’m also curious as to why the 24h window is fixed, I was expecting it to be relative to current time with this query?

Ok, so seems that adding TZ(‘Europe/Stockholm’) fixes it, so it’s an influx-problem, however then I can’t have the fill() function…?