Make over/under budget amount reflect today's difference

The over/under budget amount currently reflects the different between the budgeted amount as of the last day of the month, and the actual amount as of the current day. This is not useful as it presumes one might simply stop spending until the end of the month. It would be much more useful to know the difference between the budgeted amount as of today, and today's actual spending, as it would help make better decisions about spending for the rest of the month.