# tilwhen date engine

> Deterministic date arithmetic with auditable receipts: business days, due dates, holidays.

- name: com.tilwhen/tilwhen
- version: 1.0.1
- connection class: R0 (autonomous)
- trust: 79/100 flags: no-repository
- quality: 80/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.tilwhen%2Ftilwhen
- tools: https://api.protogrid.dev/v1/servers/com.tilwhen%2Ftilwhen/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "tilwhen": {
      "type": "http",
      "url": "https://mcp.tilwhen.com/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 99
- freshness: 85
- provenance: 55
- drivers: +dns-namespace +website +reachable +uptime-97% ~updated-32d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 80/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 9 of 9 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 2,809 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 50 (weight 15)

- pass `stability.changes`: 2 tool changes in 30 days
- fail `stability.rug_pull`: 1 tools kept their name but changed most of their description in 30 days; review before trusting them

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 9, about 2,809 tokens to load them all
- tool set hash: f454adedf309b998d38ae6527186e4cf
- tools last changed: 2026-09-27T11:55:00.370Z
- badge: [![protogrid quality](https://protogrid.dev/badge/com.tilwhen/tilwhen.svg)](https://protogrid.dev/servers/com.tilwhen/tilwhen)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

- 2026-09-27 `business_days` changed (description)
  - before: Span mode (from+to): business days between two dates, exclusive of the start day, inclusive of the end day. Add mode (days, optional date): the date N business days away. Optional holiday jurisdiction or custom calendar, and a selectable working week.
  - after: Span mode (from+to): business days between two dates, exclusive of the start day, inclusive of the end day. Add mode (days, optional date): the date N business days away. Passing from or to selects span mode and needs both; days and date are then ignored, so add mode takes its start date in date, not from. Optional holiday jurisdiction or custom calendar, and a selectable working week. For calendar days use add_days, subtract_days or days_between.
- 2026-09-27 `days_between` changed (description) **meaning changed**
  - before: Signed whole calendar days from one date to another, midnight to midnight, endpoints exclusive (the gap).
  - after: Signed whole calendar days from the from date to the to date, midnight to midnight in tz: positive when to is later, negative when it is earlier. Endpoints are exclusive, so this is the gap and consecutive dates are 1 apart. Either date may be "today", resolved in tz. For working days between two dates use business_days; to move a date by N days use add_days or subtract_days.

Full history: https://api.protogrid.dev/v1/servers/com.tilwhen%2Ftilwhen/changes

## Remotes

- https://mcp.tilwhen.com/mcp (streamable-http, auth none, reachable true, uptime30d 0.96581197)

## Packages

_none_

## Tools (9)

- `add_days`: The date N whole calendar days after a date (exclusive counting: the start date is day 0). Omit date for today in tz. For working days use business_days; for the gap between two dates use days_between.
- `business_days`: Span mode (from+to): business days between two dates, exclusive of the start day, inclusive of the end day. Add mode (days, optional date): the date N business days away. Passing from or to selects span mode and needs both; days and date are then ignored, so add mode takes its start date in date, not from. Optional holiday jurisdiction or custom calendar, and a selectable working week. For calendar days use add_days, subtract_days or days_between.
- `days_between`: Signed whole calendar days from the from date to the to date, midnight to midnight in tz: positive when to is later, negative when it is earlier. Endpoints are exclusive, so this is the gap and consecutive dates are 1 apart. Either date may be "today", resolved in tz. For working days between two dates use business_days; to move a date by N days use add_days or subtract_days.
- `explain`: Runs any operation and returns the receipt plus human-readable derivation steps. Set op, then pass the fields that operation's own tool takes. Use it when the user asks how an answer was reached.
- `holidays`: Observed public holidays with the nominal (legal) date and status: rule (statutory) or declared (officially declared for that year). Declared-only holidays are omitted for undeclared years, with a holiday_data_incomplete warning.
- `invoice_due`: Due date for Net-N payment terms (calendar days, invoice date = day 0). Optional roll-forward past weekends and, with a jurisdiction or custom calendar, public holidays.
- `next_occurrence`: The next occurrence strictly after the base date (default today) of either a tracked event slug (e.g. "christmas") or a weekday (0 = Sunday .. 6 = Saturday). Provide exactly one of event/weekday.
- `parse_date_query`: Parses queries like "90 business days from today in uganda" into a normalized operation, answers it, and returns the auditable receipt. Ambiguous dates (03/04/2027) return needsClarification instead of a guess.
- `subtract_days`: The date N whole calendar days before a date (exclusive counting: the start date is day 0). Omit date for today in tz. For working days use business_days; for the gap between two dates use days_between.