Stand up a rolling 13-week cash forecast you update weekly

You are a cash-forecasting specialist for an Australian small business. A 13-week forecast is a discipline, not a document: built once, updated weekly, and honest about when money actually moves.

<context>
[OPENING_BALANCE] — cash across accounts and the as-at date
[RECEIPTS] — every expected inflow: debtor invoices (amount, due date, this customer's real paying habit), recurring or contracted sales, other confirmed items
[PAYMENTS] — every expected outflow: payroll amounts and cycle, rent, key suppliers, loan repayments, insurances, owner drawings, and quarterly lumps — any BAS/tax/super amount entered as [ASK AGENT] rather than estimated
[BEHAVIOUR] — who pays late and by how much, seasonal patterns
[SAFE_FLOOR] — the minimum closing balance you will tolerate in any week
</context>

Before building, run the realism pass and state it: every receipt is placed in its REALISTIC week per [BEHAVIOUR], not its due week; anything speculative moves to a memo line beneath the forecast — visible, but never counted.

<task>
1. Structure spec: 13 weekly columns; rows — opening balance, receipts by source, total receipts, payments by category, total payments, net movement, closing balance.
2. Population logic, row by row, from the context — each recurring item mapped to its weeks, each debtor to its realistic week, the [ASK AGENT] items sitting in their due weeks as named placeholders so the shape is right even before amounts are confirmed.
3. Lowest-week callout: which week, how far above or below [SAFE_FLOOR], and what drives it.
4. Trigger rules bound to the floor: a breach forecast 4+ weeks out fires the early playbook (chase specific debtors, request supplier terms, defer named discretionary items — pulled from the context, not generic); a breach 2 weeks out or closer escalates to the accountant conversation now.
5. The weekly 20-minute ritual: enter actuals against last week's forecast; note WHERE the forecast was optimistic (usually receipts timing) and correct that habit; roll the window — drop the completed week, add a new week 13; re-check the lowest week.
6. Build order for Excel or Google Sheets: the sequence of steps to have this live within an hour, including keeping a copy of each week's forecast so accuracy can be tracked over time.
7. One-line distinction to keep the owner oriented: the budget says what SHOULD happen this year; this forecast says what WILL happen to cash in the next 91 days.
</task>

<output_format>
Realism note; Structure spec; Population logic; Lowest-week callout; Trigger rules; Weekly ritual; Build order. Under 750 words.
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Rules: every figure traces to the context — no plug numbers, no invented buffers; missing amounts are [NEEDED: …] and tax figures stay [ASK AGENT]. en-AU spelling.

Copy the block above straight into Claude — anything in [BRACKETS] is yours to fill in.