Possibility to calculate Riemann sum integral retroactively

Would it not be feasible to have the Riemann sum integral calculated retrospectively when creating it?
If I realise later that I need an integral, then I only have data “as of now”. I cannot have the past statistical data calculated (or I don’t know how, if it were already possible now).
The same for “Utility Meter”.

This would be extremely helpful to not lose historical data.