Calculate leftover energy for energy contract period

Hi There,

First time here. Did some research but could not find something usefull.

What I like to have:
Everybody has a contract from there energy supplier. Mine starts from 31-03 every year. So I would like to know how much energy I build up and have leftover everyday starting from 31-03.

In the summer you build up a lot of energy with the solar panels and in the winter I can use this “Buffer” to heat my house with airco’s. But I would like to know if it is possible to make an enegy meter to see the total kWh’s left.

It is possible now to generate it in the energy dashboard but then you need to make a selection everytime:

So here you can see that I have 1288.38 kWh left when calculating from 31-03 till now.

How can we make a gauge or number that represents this?