Multi-period cash and budget projection that tells you the horizon at which the arithmetic stops being trustworthy.
See it run - a worked example, 100% in this browser tab
The problem
A treasury projecting cash years out lives on a running balance where every period feeds the next, and a spreadsheet presents the year-30 figure with the same false confidence as year one, silently accumulating rounding along the way.
The local-first solution
This plugin carries an opening balance forward through your projected inflows and outflows, flags every period below a minimum reserve, and discounts the net flows to a present value. The distinctive move: the running balance is accumulated through the real GeoNum substrate kernel, so each period carries its own drift verdict and the tool reports the horizon at which the projection arithmetic has drifted past VALID. An optional net-flow volatility adds a closed-form liquidity-at-risk band and the probability of breaching the reserve at each horizon.
What it does
Multi-period balance recursion from a pasted schedule or parametric growth
Minimum-operating-reserve breach flagging, period by period
Present value of the net flows at your discount rate
Horizon-honest precision: the period at which the arithmetic drifts past VALID
Optional closed-form liquidity-at-risk band (cumulative sigma*sqrt(t))
Reserve-breach probability at each horizon via the normal CDF (no Monte-Carlo)
Honest scope
Every figure is your planning input, echoed back - a projection is only as good as its assumptions. The GeoNum verdict is the conditioning of the projection arithmetic at each horizon; the reported balance is exactly what f64 computes. For typical same-scale ledgers f64 is entirely sufficient and the verdict reads PRECISE, which is the honest answer; it would flag a wide-dynamic-range ledger where it is not. The liquidity band assumes independent normal per-period shocks. Not investment, accounting, or financial advice.
Authorities cited
Brealey, R.; Myers, S.; Allen, F. "Principles of Corporate Finance." McGraw-Hill. The discounted-cash-flow / NPV identity NPV = sum_t CF_t/(1+r)^t and the cash-budget projection method.
Higham, N.J. "Accuracy and Stability of Numerical Algorithms," 2nd ed., SIAM 2002. The error analysis of recursive summation and compensated (Kahan) summation that motivates the per-horizon precision verdict.
Association for Financial Professionals (AFP). "Treasury cash-forecasting practice." The rolling multi-period cash-flow forecast and minimum-operating-reserve concepts modeled here.
Project your cash runway
Enter your opening balance and cash schedule and project it in the browser - nothing is uploaded. Save the run to a Sandbox workspace or attach it to a Worklog case.