Haha, I was waiting for someone to ask that question! I made the budget rolling. Meaning that the budget is recalculated every day to include start of the year/month up to the present day of the month/year. That means that when your usage exactly follows the standardized distribution, it will always be 100%, no matter how far you are in the year or month.
Today (26.12.2022) as example:
The total electricity budget for this month is calculated from this sheet: Volumegrenzen Prijsplafond 2023 - Google Sheets
From start of the month (1.12) until today (26.12) the budget is 299,4 kWh (just add up the values of each day). If PBTH has registered that your actual usage this month so far is 291,9 kWh, that means you are 291,9 / 299,4 = 97,5% on target. Which is just a little bit under what the NL government says your budget should be in December for an average household.
For the yearly budget the same approach is used, starting the days from January 1st up to the present day.
