You'd get a lot of the way to what I wish YNAB4 did with couple additions connected to scheduled transactions.
Now I can achieve lots of kinds of one-time or recurring goals by estimating the transaction that they'll pay for.
- Flag a scheduled transaction as an estimate (mostly cosmetic). If an estimated transaction goes into the register, force me to interact with the amount (maybe just have focused the control and hit enter) before the "accept" action is enabled, so I don't accidentally accept it along with a bunch of other transactions.
- Add "average scheduled outflows" in addition to (or, IMO, in place of) "scheduled outflows this month" in the quick budget controls
This value would consist of two calculations:- Convert all scheduled outflows to a monthly rate and add up. This poses the obvious challenge that for daily/weekly periods the number of times per month isn't consistent. Convert these to daily, then multiply by 365.2425 / 12 for to change daily rate to monthly. This gives a funding rate that maintains average balance in the long run.
- Look ahead to the month containing the next occurrence of each scheduled transaction, assuming that all transactions occur as scheduled and the funding in any currently-blank month will be the value calculated in (1). If this balance would become negative at any point, divide an amount adequate to cover that shortfall by the number of months until the shortfall occurs (round up), and add that on. This will gradually (but in time) get the average balance up to where there any minimas due to month/week irregularity do not overspend the category, after which this part of the calculation is 0 ever after.
If "average scheduled outflows" is chosen for "fill all empty budget cells" (i.e. for the whole month), leave categories that have no scheduled outflows on or after the month blank. If you go with the YNAB4 convention of 0 == blank, this happens anyway because the calculation comes back 0. - This blends over into forecasting, but it would also be very nice to have a "Forecast Scheduled" toggle button on the budget view that is basically "show the visible budget months as if they had passed".
- Use the "average scheduled outflows" calculation in place of all blank budget categories containing containing scheduled transactions
- Show the category outflows and balance as if scheduled transactions had been entered the ledger.
- Highlight cells affected by this forecasting in some way (e.g. "penciled-in" font, lighter text color, maybe a color highlight)
- Use the "average scheduled outflows" calculation in place of all blank budget categories containing containing scheduled transactions
Now I can achieve lots of kinds of one-time or recurring goals by estimating the transaction that they'll pay for.