The Calendar Convert API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for calendar convert.
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openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Calendar Convert API
version: 2.0.0
description: Pay-per-call agents settled in USDC on Base via x402. Every response carries a signed provenance envelope.
contact:
name: WritersLogic
url: https://writerslogic.com/agents
email: agents@writerslogic.com
servers:
- url: https://agents.writerslogic.com
tags:
- name: Calendar Convert
paths:
/api/v1/calendar-convert:
post:
operationId: calendar_convert
summary: Convert dates between Gregorian and Hijri (named variants), Hebrew, Persian…
description: 'Converts a Gregorian date (or a Hebrew, Persian, Ethiopian or Hijri date) to the other calendars via the runtime''s ICU, always naming the Hijri variant (Umm al-Qura, tabular civil, tabular astronomical-epoch, ICU astronomical) and flagging when variants disagree on the day; with mode easter, returns Western (Gregorian computus) and Orthodox (Julian computus, with its Gregorian equivalent) Easter and optional moveable feasts for up to 60 years (Ash Wednesday, Trinity Sunday and Corpus Christi are Western-only and carry no Orthodox date). Covers 1900-2100 Gregorian. Calendar days begin at civil midnight here (Hebrew and Hijri days actually begin at sunset), and observed Islamic dates depend on moon sighting; it gives the computed calendar date, not the observance date.
Price: 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/calendar-convert
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- mode
properties:
mode:
type: string
enum:
- convert
- easter
date:
type: string
pattern: ^\d{4}-\d{2}-\d{2}$
maxLength: 10
description: 'convert: Gregorian date. Exactly one of date or from.'
from:
type: object
required:
- calendar
- year
- month
- day
properties:
calendar:
type: string
enum:
- hebrew
- persian
- ethiopic
- islamic-umalqura
- islamic-civil
- islamic-tbla
- islamic-icu
year:
type: integer
minimum: 1
maximum: 9999
month:
type: integer
minimum: 1
maximum: 13
description: 'Numeric month. Hebrew follows ICU: Tishri=1; leap years have Adar I=6, Adar II=7, Nisan=8 ... Elul=13; common years have Adar=6, Nisan=7 ... Elul=12.'
day:
type: integer
minimum: 1
maximum: 30
to:
type: array
maxItems: 8
items:
type: string
enum:
- hebrew
- persian
- ethiopic
- islamic-umalqura
- islamic-civil
- islamic-tbla
- islamic-icu
- hijri-all
description: 'Calendars to convert into; hijri-all returns Umm al-Qura, tabular civil and ICU astronomical (add islamic-tbla explicitly; it differs from civil by its epoch) and fails when they disagree. Default: all non-Hijri plus hijri-all.'
years:
type: array
minItems: 1
maxItems: 60
items:
type: integer
minimum: 1583
maximum: 2999
description: 'easter: Gregorian years.'
feasts:
type: boolean
description: 'easter: also list Ash Wednesday, Good Friday, Ascension, Pentecost and other moveable feasts.'
example:
mode: convert
date: '2025-06-26'
to:
- hijri-all
- hebrew
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.'
gregorian:
type: string
weekday:
type: string
conversions:
type: array
items:
type: object
properties:
calendar:
type: string
variant:
type: string
year:
type: integer
month:
type: integer
monthName:
type: string
day:
type: integer
hijriVariantsAgree:
type: boolean
easter:
type: array
items:
type: object
properties:
year:
type: integer
western:
type: string
westernWeekday:
type: string
orthodoxJulian:
type: string
orthodoxGregorian:
type: string
orthodoxWeekday:
type: string
sameDay:
type: boolean
feasts:
type: array
items:
type: object
properties:
name:
type: string
western:
type: string
orthodox:
type: string
reason:
type: string
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
tags:
- Calendar Convert
components:
securitySchemes:
x402:
type: apiKey
in: header
name: PAYMENT-SIGNATURE
description: x402 v2 payment payload (base64) sent after a 402 challenge
apiKey:
type: apiKey
in: header
name: X-API-KEY