Since this did not seem to be feasible, I was able to write my own script that does the calculations and simply inserts the values into InfluxDB.
It calculates the 00:00:00 value (to be the day’s first value) and 23:59:59 value (to be the last value). Using then max(“value”) - min(“value”) does the trick and I can quite precisely monitory the energy consumption even though I don’t receive reports at specific times.