eatme/docs/data-model/pay-rates.md

type, title, description, resource, tags, timestamp

type	title	description	resource	tags	timestamp
SQLite Table	pay_rates	Hourly rate history per employee, keyed by the date it takes effect.	backend/src/db/index.ts	data-model sqlite payroll	2026-08-16T00:00:00Z

pay_rates

Versioned hourly rate per employee. There's no valid_to column — the active rate for a given date is simply the row with the largest valid_from <= that date (getRateAt in backend/src/services/payRates.ts). A new rate implicitly ends the previous one.

Schema

Column	Type	Description
id	INTEGER PK	autoincrement
employee_id	INTEGER	references employees
hourly_rate	REAL	Kč/hour
valid_from	TEXT	YYYY-MM-DD, takes effect from this date inclusive
created_at	TEXT	ISO 8601 UTC

UNIQUE (employee_id, valid_from) — setting a rate again for the same date overwrites it (ON CONFLICT ... DO UPDATE) rather than erroring.

Behavior

• First rate ever set for an employee defaults valid_from to the employee's own created_at date when the admin doesn't specify one — so hours already worked before the admin got around to entering a rate still get paid correctly, rather than pricing at 0. This was a real bug found live: an admin set a rate today, and it didn't apply to shifts worked earlier that same month.
• Every later rate change (a raise) defaults to today instead — not retroactive. This asymmetry lives in defaultValidFrom in backend/src/services/payRates.ts and is covered by a test in backend/src/services/payroll.test.ts.

Related

• employees
• month_closures / payroll — consume getRateAt when computing earned_estimate / base_amount