# Calendar Systems – Gregorian to Islamic Tabular Civil Calendar Converter

> Calendar Systems – Gregorian to Islamic Tabular Civil Calendar Converter is a paid API for AI agents from calendar-systems.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Converts a Gregorian date to the Islamic tabular civil calendar date (or vice versa), returning month name, leap year status, observances, and a disclaimer that this is a calculated approximation, not based on moon sighting.

## Facts

- Endpoint: GET https://calendar-systems.x402tookit.com/islamic-calendar?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/calendar-systems-gregorian-to-islamic-tabular-civil-calendar-converter-155cf0cc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jOFtfeBhhJHhpvSksfBmh

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability calendar-systems-gregorian-to-islamic-tabular-civil-calendar-converter-155cf0cc
```

Example prompt: What is the Islamic Hijri tabular calendar date for March 15, 2025? Please also tell me the Islamic month name and whether it's a leap year.

## When to prefer this

Use this endpoint when you need a deterministic, algorithmically-calculated conversion between Gregorian and Islamic calendar dates. Ideal for scheduling, date display, religious planning applications, or any context needing Hijri dates without relying on regional moon-sighting announcements. Prefer over manual calculation or moon-phase-based services when a fixed, reproducible tabular result is needed.

## Known failure modes

- Missing required 'date' query parameter returns an error
- Invalid date format (not YYYY-MM-DD) causes a parse error
- Date out of supported range may return unsupported flag
- Invalid 'from' enum value (not 'gregorian' or 'islamic') causes validation failure
- Islamic date that does not exist in the tabular calendar may return an error or degraded result

## How this service works

Convert a Gregorian date to the Islamic tabular civil calendar (or back); a calculated approximation, not moon sighting.

## Output

Returns a structured object containing the corresponding Islamic calendar date (day, month number, month name, year), whether it is a leap year, the length of the month and year in days, any Islamic observances on that date, the source Gregorian date components, the weekday, and a disclaimer noting the result is a calculated tabular approximation rather than a moon-sighting-based determination.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "date"
     ],
     "properties": {
      "date": {
       "type": "string",
       "description": "YYYY-MM-DD, in the Gregorian calendar (default) or in the islamic calendar when from=islamic"
      },
      "from": {
       "enum": [
        "gregorian",
        "islamic"
       ],
       "type": "string",
       "description": "gregorian (default) or islamic: which calendar the date is written in"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "from": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "islamic": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "day": {
         "type": [
          "null",
          "number"
         ]
        },
        "text": {
         "type": [
          "null",
          "string"
         ]
        },
        "year": {
         "type": [
          "null",
          "number"
         ]
        },
        "input": {
         "type": [
          "null",
          "string"
         ]
        },
        "month": {
         "type": [
          "null",
          "number"
         ]
        },
        "leapYear": {
         "type": [
          "boolean",
          "null"
         ]
        },
        "monthName": {
         "type": [
          "null",
          "string"
         ]
        },
        "observances": {
         "type": [
          "array",
          "null"
         ],
         "items": {
          "type": "object",
          "properties": {
           "name": {
            "type": [
             "null",
             "string"
            ]
           },
           "gregorian": {
            "type": [
             "null",
         
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/calendar-systems-gregorian-to-islamic-tabular-civil-calendar-converter-155cf0cc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from calendar-systems.x402tookit.com](https://www.zero.xyz/host/calendar-systems.x402tookit.com/llms.txt)