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Function: overageApprovalWeekToPayWeek()

overageApprovalWeekToPayWeek(weekStartIso): string

Defined in: src/lib/dates/index.ts:141

Map an overage approval's stored week_start to the pay engine's Monday-anchored overage week key by snapping it FORWARD to the nearest Monday (a no-op when it is already a Monday). The single seam between billing and pay:

  • New approvals (ADR-0049) are stored on the unified Mon–Sun week, so this is the identity.
  • Legacy approvals stored on the old Sun–Sat billing week map to the next-day Monday, exactly as before — so existing approved overage keeps BOTH its billing match (on the stored Sunday week_start, against an un-migrated legacy invoice) AND its pay match (on this Monday key).

No approval rows are rewritten by the unification; this function absorbs both anchors. Once the legacy Sunday tail has fully settled it degenerates to a pure identity and can be inlined.

Parameters​

weekStartIso​

string

The approval's stored week_start as YYYY-MM-DD (Sunday legacy or Monday new).

Returns​

string

The Monday-anchored ISO pay-week start (weekStartIso snapped forward to its Monday).

Throws​

DateError if weekStartIso is not a valid YYYY-MM-DD date (propagated from fromISO).

Example​

overageApprovalWeekToPayWeek('2026-06-21'); // Sunday  → '2026-06-22' (legacy)
overageApprovalWeekToPayWeek('2026-06-22'); // Monday  → '2026-06-22' (new, identity)