Helper - change value in past of for future


for calculation of energy cost in Energy dashboard I want to use a numeric helper as entity for the tariff instead of a fixed value. I do not expect that I have to change the value often, maybe once a year. But what options do I have beside changing the value exactly at the day the new value is getting valid?

  • If there a simple possibility that I can somehow define the new value in advance to get valid at a certain date?
  • Or is there a possibility to correct the value in the past?