Convert a Gregorian date to other calendar systems and back
Convert a Gregorian date to other calendar systems and back: Islamic (both the tabular civil calendar and the Umm al-Qura variant), Hebrew, Japanese imperial era, Republic of China, Buddhist and Persian. Also computes Easter Sunday for a year in both the Gregorian and Julian reckonings. Uses the calendar support built into the runtime, with the algorithm named in every response.
Answeringour last check, 2026-09-29
1 of 1checks answered this week
23 msmedian answer time
$0.05listed price per call
$0.05price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://api.duoleads.com/v1/time/calendar
| Category | Everything else |
|---|---|
| Provider host | api.duoleads.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-29 | valid payment request | 402 | $0.05 | 23 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"date": "2026-09-28",
"to": "islamic,hebrew,japanese"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"date": {
"description": "Gregorian date YYYY-MM-DD. Required when op=convert.",
"maxLength": 32,
"pattern": "^\\d{4}-\\d{2}-\\d{2}$",
"type": "string"
},
"op": {
"default": "convert",
"description": "convert (default) a Gregorian date, or easter for a year.",
"enum": [
"convert",
"easter"
],
"maxLength": 64,
"type": "string"
},
"rite": {
"default": "western",
"description": "Easter reckoning: western (default) or eastern.",
"enum": [
"western",
"eastern"
],
"maxLength": 64,
"type": "string"
},
"to": {
"description": "Comma-separated calendar ids: islamic, islamic-umalqura, hebrew, japanese, roc, buddhist, persian. Default all.",
"maxLength": 256,
"type": "string"
},
"year": {
"description": "Year for op=easter, 326-9999.",
"maxLength": 64,
"pattern": "^[+-]?\\d+$",
"type": "string"
}
},
"required": [],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"data": {
"type": "object"
},
"meta": {
"properties": {
"computed_at": {
"type": "string"
},
"deterministic": {
"type": "boolean"
},
"disclaimer": {
"type": "string"
},
"price_usd": {
"type": "string"
},
"request_id": {
"type": "string"
},
"sources": {
"type": "array"
}
},
"required": [
"request_id",
"computed_at",
"price_usd",
"deterministic",
"disclaimer"
],
"type": "object"
},
"ok": {
"const": true,
"type": "boolean"
},
"route": {
"type": "string"
},
"version": {
"type": "string"
}
},
"required": [
"ok",
"route",
"version",
"data",
"meta"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}