How calculate range from first day of month to now


I have a metric, power_consumption_total, and I would like to calculate the consumption in the month so far. The prometheus delta function is right, my problem is to define the correct range that goes from the first day of the month to now. How can I do?

Welcome @msarti

Can you try putting now/M in the Relative time in the Query options section? Doing so will override the time dropdown selector.