Business-day deadline (clear days, cutoffs, DST) on a named or caller calendar

$0.005 USDC per call · Business, finance and compliance · POST /api/v1/business-deadline · Id business-deadline

Computes the date (and optionally the instant) a business-day deadline falls on, for an agent drafting or checking a contract, notice, SLA or partner response window: '10 clear business days' (both endpoints excluded) or 'within 10 business days' (end day counted), forward or backward, with an after-cutoff roll, caller or named holiday calendar and a DST-aware deadline time. Named calendars (US federal, Federal Reserve, NYSE, UK bank holidays) carry a source, as-of date and supported range and answer `unsupported` outside it. It does not interpret contract wording, know your jurisdiction's deeming rules, or read the clock.

What you get

Off-by-one on 'clear days', a Friday-after-cutoff notice or a deadline in a DST gap are the usual ways a deadline is missed.

Call it

Send the JSON body below to https://agents.writerslogic.com/api/v1/business-deadline. An unpaid request answers 402 with the price and how to pay; a request that fails with a 5xx status is not charged.

curl -i -X POST https://agents.writerslogic.com/api/v1/business-deadline \
  -H 'content-type: application/json' \
  -d '{"start":"2026-12-18","days":10,"counting":"clear","calendar":"us-federal"}'

Input

Field	Type	Required	Description
`start`	string; length 0..19	yes	Local date YYYY-MM-DD, or local date-time YYYY-MM-DDTHH:MM[:SS] (the notice/receipt moment). Never read from the clock.
`days`	integer; 0..3650	yes
`counting`	string; one of "clear", "elapsed"	yes	clear: days strictly between start and deadline, so the deadline is business day N+1. elapsed: the deadline is business day N after start (the end day is counted).
`direction`	string; one of "after", "before"	no	Default after. before counts backward from start (for 'at least N days before the hearing').
`calendar`	string; one of "us-federal", "us-federal-reserve", "nyse", "us-equities-settlement", "uk-england-and-wales", "uk-scotland", "uk-northern-ireland", "weekends-only", "caller"	yes	Named holiday calendar with a source and supported date range (outside it the answer is unsupported), weekends-only (Saturday/Sunday only), or caller (only the holidays you list).
`holidays`	array<string; length 0..10>; max 400 items	no	Extra non-business dates YYYY-MM-DD (company closures, a calendar we do not carry).
`weekend`	array<integer; 0..6>; max 6 items	no	Non-business weekdays, 0=Sunday..6=Saturday. Default [0, 6]; use [5, 6] for a Friday/Saturday weekend.
`cutoff`	string; length 0..5	no	Local HH:MM. With a date-time start (direction after), a start strictly later than the cutoff, or on a non-business day, is deemed received on the next business day. 17:00 exactly is on time. Without cutoff there is no roll.
`deadlineTime`	string; length 0..5	no	Local HH:MM at which the deadline expires on the deadline date; needs timeZone to produce an instant.
`timeZone`	string; length 0..64	no	IANA zone for deadlineTime.
`disambiguation`	string; one of "earlier", "later"	no	How to read a deadline time that falls in a DST gap (earlier: before-gap offset reading backward; later: shifted forward) or overlap (earlier/later occurrence). Without it, a gap or overlap returns unknown with both candidates.
`claimedDeadline`	string; length 0..10	no	A deadline date someone asserted; the check fails with the computed date if it differs.

Example request body

{
  "start": "2026-12-18",
  "days": 10,
  "counting": "clear",
  "calendar": "us-federal"
}

Result

The response is { "data": ..., "_provenance": ... }. data carries these fields; _provenance is a signed W3C Verifiable Credential with a C2PA-style manifest, checked free at POST /api/v1/verify-provenance.

Field	Type	Required	Description
`status`	string; one of "pass", "fail", "unknown", "unsupported"	no	pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.
`deadlineDate`	string	no
`weekday`	string	no
`effectiveStart`	string	no
`startRolled`	boolean	no
`startRollReason`	string	no
`businessDaysCounted`	integer	no
`clearBusinessDays`	integer	no
`skipped`	array<object>	no	Non-business days stepped over (first 60).
`skippedCount`	integer	no
`deadlineLocal`	string	no
`deadlineUtc`	string	no
`wallTimeKind`	string; one of "normal", "gap", "overlap"	no
`candidatesUtc`	array<string>	no
`reason`	string	no
`witnesses`	array<object>	no
`versions`	object	no	Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
`limits`	array<string>	no
`deterministic`	boolean	no	Always true: pure code, no model.

Pay and connect

Available through: x402 (USDC on Base), MCP. MCP clients reach it through the calendar-deadline-kit package.

Machine-readable

This agent as JSON (schemas, example, OpenAPI operation)
Free signed sample response
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