Retainer OS — Notion or Excel, hours bank + invoice rhythm
By Nydaymuse · Updated
What belongs in a retainer OS?
Four linked lists: the retainer agreement (fee, hours, rollover rule), the monthly hours bank, the deliverables those hours bought, and the invoice rhythm. One home base is enough.
Retainers die from mystery hours: unused time that silently rolls forever, or free extras that never hit an invoice. Freelancers need a calm month-close — not another billing SaaS.
Harbor is Nydaymuse’s $12 dual-format retainer OS: Retainers, Hours_Bank, Deliverables, and Invoices as Notion CSVs and as an Excel / Sheets workbook with Month_Close. Pick one.
Why retainers need a month-close
A month-close brings used hours, rollover rules, and the next invoice into one review. Harbor keeps the job fixed (bank + rollover + invoice day) and lets the buyer choose Notion or a workbook.
Harbor is not a full pipeline. Pair it with Lane when retainers start as projects, Ops when invoices age, and free Slip for a one-page invoice layout.
Rollover rules that stay boring
| Rule | Meaning |
|---|---|
| Unused hours roll 1 month | Leftover moves once; then expires |
| Rollover cap | Max hours that may enter next month |
| No rollover | Use-it-or-lose-it within the month |
Write the rule once per retainer. Use rolled-in hours before current-month included hours. Unused rolled-in hours expire at month-end; only unused current-month included hours can roll again, up to the cap. Apply this on Month_Close before drafting next invoices.
Month-close checklist
- Reconcile hours_used vs deliverable hours.
- Apply rollover rule + cap; note expired hours. Manually copy the same retainer’s final rollover_out into the immediately next month’s rolled_in once only.
- Draft next-month invoices on each invoice_day.
- Chase anything still Sent past due.
- Pause retainers that should not silently continue.
Harbor — dual Notion + Excel pack ($12)
One zip. Notion CSVs + import README, or open Harbor-Retainer-OS.xlsx (Dashboard, Retainers, Hours_Bank, Deliverables, Invoices, Month_Close). Replace SAMPLE input values while preserving formulas. Buy once. No support.
Rollover checks and manual setup
Example: 0 included + 6 rolled-in − 0 used leaves 6 available within the month, but 0 rollover out. With 2 included + 6 rolled-in − 0 used, only 2 may roll if the cap allows it. The 6 old hours expire rather than being carried again.
The workbook flags missing or invalid hours-bank inputs with CHECK. Resolve these before using Dashboard hours totals. Retainer lookup/check rows are 2–45; bank formulas and Dashboard bank totals cover rows 2–47. Extend all related formulas, lookup and summary ranges, filters and validation together for more rows.
Month-to-month transfer remains manual. Invoice status and aging are manual too: open invoices includes Draft + Sent + Overdue, while Collected includes Paid. The checks do not validate invoice amounts/dates, duplicate month rows or actual previous-month transfers.
Forced native recalculation was tested in LibreOfficeDev 26.8.0.0.alpha0, a development build. Excel desktop, Google Sheets and actual Notion UI/import were not tested. Enable automatic calculation, fully recalculate after opening/importing and editing, and verify a changed input updates the total. Notion CSV calculated columns are sample values: configure properties and live formulas manually with the import guide.
Frequently asked questions
Should I use Notion and Excel at the same time?
No. Pick one home base. Harbor includes both formats so you can choose.
Is Harbor a live Notion duplicate link?
No. You import CSVs (or rebuild from the outline).
How is Harbor different from Lane or Ops?
Lane is Lead→Paid pipeline across clients. Ops is aging/money depth. Harbor is the dual-format retainer operating pack: hours bank + rollover + month-close invoice rhythm.