Forecasting cash on a business-day clock
The payment terms that govern your money are counted in business days, not calendar days. Forecast on the calendar and you will always be surprised by the shortfall.
QScope Team · 18 May 2026 · 6 min read
A cash flow forecast is a promise about dates. On an Australian job the dates that matter are set by the Security of Payment Act, and every one of them is counted in business days. A forecast that counts in calendar days is optimistic by design, and the gap shows up exactly when the account is tightest.
Where the days come from
Each receipt is a chain of statutory steps, and each step is a business-day window. Start at the reference date, add the time to serve the claim, the time for the payment schedule, and the time to payment.
- Reference date. The earliest the claim can be served, usually monthly.
- Payment schedule window. Ten business days in New South Wales and Victoria, fifteen in Queensland and Western Australia.
- Payment window. The statutory or capped term, which again differs by state and by tier in the chain.
Why calendar forecasting lies
Ten business days is never ten calendar days. Two weekends inside a window add four days, and a public holiday adds another. Across a run of claims those slippages compound, so a forecast that assumed calendar dates can be a fortnight adrift by the middle of the job. The money does arrive. It arrives later than the spreadsheet said, and the difference is real cash you needed.
Holidays are not uniform
Public holidays are excluded from business-day counts, and they are not the same across states. A job in Queensland and a job in Victoria will step over different days in the same month. A forecast that hard-codes one calendar of holidays for a business working across borders will misdate half its receipts.
Forecast the outflows too
Cash flow is both sides. As a head contractor you receive on one business-day clock and pay subcontractors on another, and in most states the subcontractor payment window is longer than the one above it. That gap is working capital, and it only reads correctly when both legs are counted in business days from their own triggers rather than netted off on a calendar.
What good looks like
A useful forecast starts every receipt at its reference date, runs the schedule and payment windows in business days for the state that governs the job, and steps over the right public holidays. Do that and the forecast stops being a hope and starts being a plan you can borrow against.
QScope forecasts each receipt from the reference date, counts the schedule and payment windows in business days for the governing state, and steps over public holidays for you.