{"id":"date-claim-check","title":"Does this date fall on the claimed weekday? (batch, year boundaries and leap days)","description":"Checks up to 200 claims 'Monday 2026-12-28' against the proleptic Gregorian calendar and reports the real weekday, whether the date exists (2026-02-29 does not), and the nearest date carrying the claimed weekday; a claim 'Friday, 13 March' without a year returns the years in a range where it holds. Built for an agent verifying dates in a document, email or itinerary. Gregorian only (no Julian dates before 1582 reform), no time zones, and it does not guess which year was meant.","roi":"Wrong weekday-date pairs are the commonest hallucinated date error; one call checks a whole itinerary.","audience":"business","package":"calendar-deadline-kit","channels":["x402","mcp"],"endpoint":{"method":"POST","url":"https://agents.writerslogic.com/api/v1/date-claim-check","path":"/api/v1/date-claim-check","contentType":"application/json"},"price":{"amount":"0.005","currency":"USDC","network":"base","perCall":true,"failedCallsCharged":false},"inputSchema":{"type":"object","additionalProperties":false,"required":["items"],"properties":{"items":{"type":"array","minItems":1,"maxItems":200,"items":{"type":"object","required":["weekday"],"properties":{"date":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","maxLength":10,"description":"YYYY-MM-DD."},"monthDay":{"type":"string","pattern":"^\\d{2}-\\d{2}$","maxLength":5,"description":"MM-DD when the year is unknown; needs fromYear and toYear."},"weekday":{"type":"string","pattern":"^[A-Za-z]{3,9}\\.?$","maxLength":10,"description":"Monday, Mon, mon ..."}}}},"fromYear":{"type":"integer","minimum":1583,"maximum":2999},"toYear":{"type":"integer","minimum":1583,"maximum":2999}}},"resultSchema":{"type":"object","properties":{"status":{"type":"string","enum":["pass","fail","unknown","unsupported"],"description":"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."},"items":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"date":{"type":"string"},"dateExists":{"type":"boolean"},"actualWeekday":{"type":"string"},"claimedWeekday":{"type":"string"},"matches":{"type":"boolean"},"nearestMatchingDate":{"type":"string"},"matchingYears":{"type":"array","items":{"type":"integer"}}}}},"witnesses":{"type":"array","items":{"type":"object","properties":{"ruleId":{"type":"string"},"detail":{"type":"string"},"path":{"type":"string","description":"JSON pointer or dotted path into the input."},"offset":{"type":"integer"},"index":{"type":"integer"},"expected":{"description":"What the rule required."},"actual":{"description":"What the input had."}}}},"versions":{"type":"object","description":"Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile)."},"limits":{"type":"array","items":{"type":"string"}},"deterministic":{"type":"boolean","description":"Always true: pure code, no model."}}},"outputSchema":{"type":"object","properties":{"data":{"type":"object","properties":{"status":{"type":"string","enum":["pass","fail","unknown","unsupported"],"description":"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."},"items":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"date":{"type":"string"},"dateExists":{"type":"boolean"},"actualWeekday":{"type":"string"},"claimedWeekday":{"type":"string"},"matches":{"type":"boolean"},"nearestMatchingDate":{"type":"string"},"matchingYears":{"type":"array","items":{"type":"integer"}}}}},"witnesses":{"type":"array","items":{"type":"object","properties":{"ruleId":{"type":"string"},"detail":{"type":"string"},"path":{"type":"string","description":"JSON pointer or dotted path into the input."},"offset":{"type":"integer"},"index":{"type":"integer"},"expected":{"description":"What the rule required."},"actual":{"description":"What the input had."}}}},"versions":{"type":"object","description":"Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile)."},"limits":{"type":"array","items":{"type":"string"}},"deterministic":{"type":"boolean","description":"Always true: pure code, no model."}}},"_provenance":{"type":"object","description":"C2PA-aligned manifest and W3C VC 2.0 (eddsa-jcs-2022) issued by the hub DID; verify at POST /api/v1/verify-provenance"}},"required":["data","_provenance"]},"example":{"items":[{"date":"2026-12-28","weekday":"Monday"},{"date":"2027-01-01","weekday":"Thursday"},{"date":"2026-02-29","weekday":"Sunday"}]},"openapiOperation":{"operationId":"date_claim_check","summary":"Does this date fall on the claimed weekday? (batch, year boundaries and leap days)","description":"Checks up to 200 claims 'Monday 2026-12-28' against the proleptic Gregorian calendar and reports the real weekday, whether the date exists (2026-02-29 does not), and the nearest date carrying the claimed weekday; a claim 'Friday, 13 March' without a year returns the years in a range where it holds. Built for an agent verifying dates in a document, email or itinerary. Gregorian only (no Julian dates before 1582 reform), no time zones, and it does not guess which year was meant.\n\nPrice: 0.005 USDC on Base (x402).","x-x402-price-usdc":"0.005","x-x402-amount":"5000","x-payment-info":{"protocols":["x402"],"price":{"mode":"fixed","currency":"USD","amount":"0.005"}},"x-audience":"business","x-sample-url":"https://agents.writerslogic.com/api/v1/samples/date-claim-check","security":[{"x402":[]},{"apiKey":[]}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":["items"],"properties":{"items":{"type":"array","minItems":1,"maxItems":200,"items":{"type":"object","required":["weekday"],"properties":{"date":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","maxLength":10,"description":"YYYY-MM-DD."},"monthDay":{"type":"string","pattern":"^\\d{2}-\\d{2}$","maxLength":5,"description":"MM-DD when the year is unknown; needs fromYear and toYear."},"weekday":{"type":"string","pattern":"^[A-Za-z]{3,9}\\.?$","maxLength":10,"description":"Monday, Mon, mon ..."}}}},"fromYear":{"type":"integer","minimum":1583,"maximum":2999},"toYear":{"type":"integer","minimum":1583,"maximum":2999}}},"example":{"items":[{"date":"2026-12-28","weekday":"Monday"},{"date":"2027-01-01","weekday":"Thursday"},{"date":"2026-02-29","weekday":"Sunday"}]}}}},"responses":{"200":{"description":"Paid result with provenance","content":{"application/json":{"schema":{"type":"object","properties":{"data":{"type":"object","properties":{"status":{"type":"string","enum":["pass","fail","unknown","unsupported"],"description":"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."},"items":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"date":{"type":"string"},"dateExists":{"type":"boolean"},"actualWeekday":{"type":"string"},"claimedWeekday":{"type":"string"},"matches":{"type":"boolean"},"nearestMatchingDate":{"type":"string"},"matchingYears":{"type":"array","items":{"type":"integer"}}}}},"witnesses":{"type":"array","items":{"type":"object","properties":{"ruleId":{"type":"string"},"detail":{"type":"string"},"path":{"type":"string","description":"JSON pointer or dotted path into the input."},"offset":{"type":"integer"},"index":{"type":"integer"},"expected":{"description":"What the rule required."},"actual":{"description":"What the input had."}}}},"versions":{"type":"object","description":"Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile)."},"limits":{"type":"array","items":{"type":"string"}},"deterministic":{"type":"boolean","description":"Always true: pure code, no model."}}},"_provenance":{"type":"object","description":"C2PA-aligned manifest and W3C VC 2.0 (eddsa-jcs-2022) issued by the hub DID; verify at POST /api/v1/verify-provenance"}},"required":["data","_provenance"]}}}},"400":{"description":"Invalid request (no payment consumed)","content":{"application/json":{"schema":{"type":"object","properties":{"error":{"type":"string"},"code":{"type":"string"}}}}}},"401":{"description":"Invalid X-API-KEY","content":{"application/json":{"schema":{"type":"object","properties":{"error":{"type":"string"},"code":{"type":"string"}}}}}},"402":{"description":"Payment required or invalid","content":{"application/json":{"schema":{"type":"object","description":"x402 v2 PaymentRequired (also base64 in the PAYMENT-REQUIRED header)","properties":{"x402Version":{"type":"integer"},"error":{"type":"string"},"code":{"type":"string"},"resource":{"type":"object"},"accepts":{"type":"array","items":{"type":"object"}},"extensions":{"type":"object"}}}}}},"502":{"description":"Upstream failure; the payment is released or not settled","content":{"application/json":{"schema":{"type":"object","properties":{"error":{"type":"string"},"code":{"type":"string"}}}}}}}},"links":{"docs":"https://agents.writerslogic.com/docs/date-claim-check/","docsJson":"https://agents.writerslogic.com/docs/date-claim-check.json","sample":"https://agents.writerslogic.com/api/v1/samples/date-claim-check","openapi":"https://agents.writerslogic.com/openapi.json","catalog":"https://agents.writerslogic.com/api/v1/catalog","verifyProvenance":"https://agents.writerslogic.com/api/v1/verify-provenance","index":"https://agents.writerslogic.com/docs/index.json"}}