Savings Goal Contribution Planner

• Enter current and positive target balances with at most two decimal places, an original start date and an inclusive deadline.
• Deposits begin on the first monthly anniversary after the start. Each month uses the original day, clamped to its final valid day when needed.
• Select Build equal-cent contribution schedule. Extra remainder cents go to the earliest dates; every eligible date remains, including zero-cent deposits.
• Download savings-contributions.json to inspect every date, deposit, cumulative sum and resulting balance.

A shortfall of 0.13 across 12 eligible dates gives 0.02 on the first date and 0.01 on each of the other 11 dates.

• Dates must be exact Gregorian YYYY-MM-DD in years 0001 through 9999, with deadline at or after start. Unsigned amounts have at most 18 total coefficient digits and 2 fractional digits.
• At most 1,024 input UTF-16 units, 1,200 eligible funding dates, 4,096 exact-intermediate digits, 1 MiB complete output and 30 seconds. No eligible funding date or an eligible 1,201st date refuses.
• Funding-required schedules retain every date, total exactly the shortfall and differ by at most one cent per installment. Current balance at or above target produces an empty schedule and preserves surplus after all inputs are validated.
• Zero-interest arithmetic only: no returns, fees, inflation, compounding, investment forecast or savings or financial advice.