holdbackcalc

Prompt-payment and holdback deadlines for Alberta and Ontario construction work — verified rules only. Give it an anchor date (invoice received, payment received, lien trigger event, contract anniversary); it gives back a dated schedule you can drop into a calendar or CI reminder.

Not legal advice. An administrative date calculator. Every constant was verified against official sources in October 2026 — and everything we could not verify is deliberately not encoded: run holdbackcalc what-we-dont-encode to see the holes.

Install

pip install holdbackcalc

Alberta

holdbackcalc ab-invoice 2026-01-01        # proper invoice received
holdbackcalc ab-sub-payment 2026-03-02    # owner's payment received by the contractor

Deliberately blank: holdback release — Alberta's statutory holdback percentage and release clock could not be verified from official text, so no date is invented.

Ontario

holdbackcalc on-lien 2026-01-01           # from the trigger event (e.g. publication of substantial performance)
holdbackcalc on-holdback 2026-01-01       # 10% holdback schedule from the same event
holdbackcalc on-invoice 2026-06-01        # proper-invoice deficiency window (2026 rules)
holdbackcalc on-annual 2026-01-01         # annual holdback release, contracts ≥ Jan 1 2026

--json gives a machine-readable schedule for automation.

What it does NOT encode

$ holdbackcalc what-we-dont-encode
  - AB: statutory holdback percentage and the post-substantial-performance release clock
  - AB: substantial-performance payment deadline and base-building/partial-performance treatment
  - AB: detailed adjudication filing deadlines
  - ON: any 'first 90 days of contract' short lien period (not found in the current Act)
  - ON: a general 45-day pleadings deadline (not found in the current Act)

These were checked against official text in October 2026 and could not be confirmed. A calculator that guesses a legal deadline is worse than no calculator.

Sources

• Alberta prompt payment overview: https://www.alberta.ca/prompt-payment-rules-for-construction-industry
• Prompt Payment and Adjudication Regulation, Alta Reg 23/2022: https://open.alberta.ca/publications/2022_023
• Ontario Construction Act (consolidated to Jan 1, 2026): https://www.ontario.ca/laws/statute/90c30
• 2026 amendments summary: https://cassels.com/insights/the-construction-act-whats-new-in-the-new-year/

Notes

• All offsets are calendar days from the anchor date you pass in.
• Deadlines that depend on a later event (e.g. pass-down timing) print as reminders with no date unless you supply the trigger.
• Pair with clearancewatch for the coverage side of job compliance.

License

MIT-style: use it, ship it, no warranty.