# Time of day and duration

**Test family:** `DUR`

- **DUR-001** Establish 12/24-hour format and test 00:00, 12:00 AM/PM, 23:59, and invalid 24:00 policy.
- **DUR-002** Duration uses explicit units; `1.5 hours`, `90 minutes`, and `01:30` round-trip consistently if equivalent.
- **DUR-003** Test zero, negative, sub-unit precision, very long duration, and overflow across day boundaries.
- **DUR-004** Elapsed duration uses monotonic time; wall-clock or DST changes do not make it negative/wrong.
- **DUR-005** Paused/resumed timers exclude/include time as promised and survive refresh, sleep, offline, and concurrent control.
- **DUR-006** Human formatting does not round away decision-relevant thresholds.

## Comprehensive per-item coverage

- **DUR-007** Exercise absent, null, empty, zero, false, ordinary, minimum, maximum, below-minimum, above-maximum, and unknown values distinctly.
- **DUR-008** Probe powers-of-two and representation boundaries around `7/8/9`, `15/16/17`, `31/32/33`, `63/64/65`, and storage-specific limits.
- **DUR-009** Use negative, fractional, high-precision, exponential, signed-zero, NaN/infinity, overflow, underflow, and rounding cases where the type can receive them.
- **DUR-010** Use labels or serialized values containing emoticons, emoji, kaomoji, accents, RTL, combining marks, confusables, and invisible characters.
- **DUR-011** Compare UI, API, import, database, cache, queue, analytics, search index, notification, and export representations; preserve one authoritative meaning.
- **DUR-012** Send wrong types, missing fields, extra fields, duplicate keys, unknown enum members, malformed encodings, and schema-version mismatches.
- **DUR-013** Bypass client min/max/step/format constraints; enforce the server and persistence contract without clipping or coercing silently.
- **DUR-014** Switch locale, numbering system, decimal/group separator, calendar, currency, time zone, and direction; separate display formatting from stored value.
- **DUR-015** Sort, filter, group, aggregate, compare, search, paginate, and chart boundary and null values; keep ordering and totals coherent.
- **DUR-016** Create and update concurrently from two sessions; prevent lost updates, duplicate identities, and stale derived values.
- **DUR-017** Retry writes and reads across timeout, disconnect, failover, and replica lag; expose stale or uncertain state rather than false certainty.
- **DUR-018** Migrate old, missing, malformed, and newly extended values forward and backward where supported; preserve auditability and rollback.
- **DUR-019** Verify permissions at field, record, tenant, export, analytics, log, cache, and backup layers; redact consistently.
- **DUR-020** Use inert markup, SQL, template, CSV-formula, path, and log canaries in any textual representation; encode for each output context.
- **DUR-021** Check accessible names, units, errors, table headers, announcements, and non-color distinctions for input and display.
- **DUR-022** Measure validation, calculation, query, sort, aggregate, import, and export behavior at normal and supported scale.
- **DUR-023** Verify derived totals, counters, scores, dates, and statuses update atomically with source data or expose reconciliation state.
- **DUR-024** Delete, restore, archive, expire, retain, and purge values; distinguish tombstone, null, zero, redaction, and absence.
- **DUR-025** Record source, actor, old/new value, unit, time, version, and reason without leaking secrets or prohibited personal data.
- **DUR-026** Reconcile after partial failure, cache corruption, duplicate message, and delayed index update; detect and repair divergence.

[Back to Numbers, money, dates, and time index](../../numbers-money-time.md)
