WTH can I not specify when the energy billing period starts

A lot of people have energy billed per month but not necessarily starting on the 1st of each month (e.g. it’s always the 5th of the month etc).

Would be nice to have a way to shift each month’s starting day to account for when the bills are dated for Otherwise the energy doesn’t match

The same goes for the billing year, which does not necessarily start in January (in my case, it starts in September). Being able to shift that as well would be great!