The ai-bookkeeper project works out when federal payroll tax deposits are due. Its tests had been written from our own reading of the rules, which proves only that the code agrees with us. Publication 15 (2026) prints worked examples, so we turned two of them into tests.
- Fir Co. A semiweekly depositor owes $110,000 on Monday and must deposit it Tuesday. Tuesday's extra $30,000 is not added to it and is due Friday.
- $95,000 then $10,000. $95,000 on a Tuesday and $10,000 on the Wednesday are in different deposit periods, so the next-day rule never fires: Friday and the following Wednesday.
Both passed without a code change. That is a small result, but it is a check against the source, not against our own assumptions. These are still hand-made registers, not a real payroll provider's report, and this is not tax advice.