Here's how billing/due_dates.py behaves today:

• Business-day counting (add_business_days, lines 4–12): It starts the day after start and counts only Mon–Fri. Holidays aren't considered, so a public holiday counts as a working day. The function has no country parameter.
• Due-date calculation (invoice_due_date, lines 15–21): It adds terms_days business days (default 10) to the issue date. Then it adds one calendar day when issued.weekday() >= 4 (lines 19–20). That condition covers Friday, Saturday and Sunday, not just Friday. A 10-day term always lands on a Friday for those issue days, so the extra day makes the due date a Saturday. For example, an invoice issued Fri 2026-10-02 is due Sat 2026-10-17. Removing the adjustment makes it Fri 2026-10-16. Anyone who has seen the current Saturday dates should know they will move one day earlier.
• Where holiday support plugs in: The weekend check at line 10 (if current.weekday() < 5) is the place to also skip holidays. To do that, add_business_days and invoice_due_date would take a country argument (or a set of holiday dates) and pass it down. A small loader would read the per-country holidays.json once and cache it, starting with US and DE. Lines 18–20 come out at the same time, as planned. terms_days=10 stays as it is.

I haven't changed any code. Two things to settle before November: what happens for a country that has no holidays.json (fail, or fall back to weekdays only), and whether the JSON files will include future years so dates stay correct around year-end.

Handoff document written by the skill:

Handoff: holiday support + removing the Friday adjustment in billing due dates

Date: 2026-10-04
Repo: <workdir> (branch main, clean, single commit fc8800b seed)
Next session's job: add public-holiday support and remove the Friday "+1 day" adjustment.

No code has been changed yet. The user said not to touch code in the previous session.

Decisions from today's planning meeting (not recorded anywhere else)

1. The Friday "+1 day" adjustment in invoice_due_date is a bug. It will be removed.
2. Add public-holiday support by loading a holidays.json file per country. Start with US and DE.
3. terms_days keeps its default of 10.
4. Finance wants this released before the November 2026 invoicing run.

Relevant files

• billing/due_dates.py: the whole module, about 20 lines. Read it first.
  • add_business_days (lines 4–12): skips weekends only. The check at line 10 (current.weekday() < 5) is where holiday skipping goes.
  • invoice_due_date (lines 15–21): lines 18–20 hold the adjustment that is being removed.
• tests/test_due_dates.py: only two tests. Neither covers the Friday adjustment or holidays.
• No holidays.json files and no loader exist yet. The location and format still need to be chosen.

Facts established in the previous session

• The adjustment condition is issued.weekday() >= 4. It fires for invoices issued on Fri, Sat and Sun, not just Friday.
• For those issue days, a 10-business-day term lands on a Friday. The +1 then makes the due date a Saturday. For example, an invoice issued Fri 2026-10-02 is currently due Sat 2026-10-17 and should be due Fri 2026-10-16. Removing the bug moves these dates one day earlier. This is worth mentioning in the PR or release notes for finance.

Suggested approach (not yet agreed with the user)

• Add a country parameter (or an injected set of holiday dates) to add_business_days and invoice_due_date, and pass it down.
• Add a small cached loader that reads per-country holidays.json files, with US and DE first.
• Delete lines 18–20 of due_dates.py and update the docstring or comment.
• Tests to add: Fri/Sat/Sun issue dates without the +1, a due date pushed past a US holiday, a due date pushed past a DE holiday, and a check that the terms_days default stays 10.

Open questions for the user

• What should happen for a country with no holidays.json: raise an error, or fall back to weekdays only?
• Which years should the JSON files cover? Due dates near year-end need next year's holidays.
• Where should the JSON files live, and what schema should they use (for example, a list of ISO date strings)?
• Is country required, or optional with a default? Existing callers and tests currently pass no country.

Suggested skills

• code-review: review the diff before committing or opening a PR.
• simplify: optional cleanup pass after the change is in.

Run the tests with pytest from the repo root. Commit and open a PR only if the user asks, and create a branch off main first.

I've written the handoff document for the next session at <system temp folder>/handoff-billing-holidays-2026-10-04.md. It's in the OS temp folder, not in the repo.

It covers:

• Meeting decisions: the four decisions from today's planning meeting, which aren't recorded anywhere else.
• Where the changes go: the line numbers in billing/due_dates.py for removing the Friday adjustment and adding holiday skipping.
• Current behaviour: the adjustment fires for invoices issued on Friday, Saturday and Sunday, and it produces Saturday due dates. Finance should be told those dates will move one day earlier.
• Test gaps: tests/test_due_dates.py has only two tests, and neither covers the adjustment or holidays.
• Open questions: what happens for a country with no holiday file, which years the files cover, where the files live and their format, and whether a country must always be given.
• Suggested skills: code-review and simplify.

I haven't changed any code, and the document contains no personal information or credentials.