Mayan Calendar API

GET

Display the Mayan Long Count, Tzolkin, and Haab date for any day.

Mayan Calendar converts Gregorian dates to the ancient Mayan calendar system. Returns the Long Count, Tzolkin (260-day sacred calendar), and Haab (365-day civil calendar) dates.

Try it — live request, no key required

Request

GETapi.apiverve.com/v1/mayancalendar?date=2024-12-21

Query parameters

datestring

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "gregorian": "2024-12-21",
    "longCount": {
      "formatted": "13.0.12.3.3",
      "baktun": 13,
      "katun": 0,
      "tun": 12,
      "winal": 3,
      "kin": 3
    },
    "tzolkin": {
      "number": 6,
      "dayName": "Akbal",
      "formatted": "6 Akbal"
    },
    "haab": {
      "day": 6,
      "monthName": "Kankin",
      "formatted": "6 Kankin"
    },
    "calendarRound": "6 Akbal 6 Kankin",
    "daysSinceEpoch": 1876383
  }
}

About the Mayan Calendar API

Uses the GMT (Goodman-Martinez-Thompson) correlation constant for accurate conversion. Ideal for educational content, historical research, and cultural applications.

What people use it for

Educational Tools: Teach about ancient Mesoamerican calendar systems
Cultural Applications: Display Mayan dates for heritage and cultural apps
Historical Research: Convert dates for archaeological and historical study
Novelty Apps: Generate personalized Mayan birth dates

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON: Default REST response
XML: Markup format
YAML: Human-readable
CSV: Tabular export
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use Mayan Calendar

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.on VerveSheets Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.on VerveContext

Questions.

Common questions about the Mayan Calendar API.

Read the docs →

Which Mayan calendar systems are supported?

The API converts Gregorian dates into three Mayan systems: the Long Count, the 260-day Tzolkin sacred calendar, and the 365-day Haab civil calendar. On paid plans, it also returns the combined Calendar Round and total days elapsed since the Mayan epoch.

What would 10,000 date conversions cost me?

A volume of 10,000 conversions takes 20,000 credits, which uses a tenth of the Starter plan's 200,000 monthly credits. Paid usage works out to about $0.30 per 1,000 calls. The Free plan includes 100 calls per month for testing.

Are individual calendar cycle numbers included on the Free plan?

No. The Free plan provides formatted strings for the Long Count, Tzolkin, and Haab dates. Granular numeric components—such as baktun, katun, tun, winal, kin, sacred day numbers, month names, and the Calendar Round—are premium fields unlocked on Starter and above.

Which correlation method is used to align the calendars?

The API relies on the GMT (Goodman-Martinez-Thompson) correlation constant, the standard historical benchmark used by researchers to synchronize the Mayan Long Count with the Gregorian calendar.

What input format does the API expect?

Dates must be passed as Gregorian calendar strings in standard YYYY-MM-DD format. Providing other formats or invalid date values will fail to convert.

Can I use these date conversions in a commercial educational product?

Yes, commercial use is permitted on any paid plan. You can freely display the converted Mayan calendar data within your educational tools, games, or publications, provided you do not resell the raw API data directly.

Request parameters — GET /v1/mayancalendar

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Parameter	Type	Example	Description
`date`Required	string	`2024-12-21`	The Gregorian date in YYYY-MM-DD format date

Example request

1
2

curl "https://api.apiverve.com/v1/mayancalendar?date=2024-12-21" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — GET /v1/mayancalendar

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "gregorian": "2024-12-21",
    "longCount": {
      "formatted": "13.0.12.3.3",
      "baktun": 13,
      "katun": 0,
      "tun": 12,
      "winal": 3,
      "kin": 3
    },
    "tzolkin": {
      "number": 6,
      "dayName": "Akbal",
      "formatted": "6 Akbal"
    },
    "haab": {
      "day": 6,
      "monthName": "Kankin",
      "formatted": "6 Kankin"
    },
    "calendarRound": "6 Akbal 6 Kankin",
    "daysSinceEpoch": 1876383
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`gregorian`	string	`"2024-12-21"`	The input Gregorian date in YYYY-MM-DD format
`longCount`	object	`{...}`
`formatted`	string	`"13.0.12.3.3"`	Mayan Long Count formatted as baktun.katun.tun.winal.kin
`baktun`Premium	number	`13`	Long Count baktun component (cycle of 400 tuns)
`katun`Premium	number	`0`	Long Count katun component (cycle of 20 tuns)
`tun`Premium	number	`12`	Long Count tun component (cycle of 18 winals)
`winal`Premium	number	`3`	Long Count winal component (cycle of 20 kins)
`kin`Premium	number	`3`	Long Count kin component (day unit in Mayan calendar)
`tzolkin`	object	`{...}`
`number`Premium	number	`6`	Tzolkin sacred calendar day number (1-13)
`dayName`Premium	string	`"Akbal"`	Tzolkin day name from 20-day Mayan sacred cycle
`formatted`	string	`"6 Akbal"`	Tzolkin date formatted as number and day name
`haab`	object	`{...}`
`day`Premium	number	`6`	Haab civil calendar day number (0-19 or 0-4)
`monthName`Premium	string	`"Kankin"`	Haab month name from 18-month Mayan civil calendar
`formatted`	string	`"6 Kankin"`	Haab date formatted as day and month name
`calendarRound`Premium	string	`"6 Akbal 6 Kankin"`	Calendar Round combining Tzolkin and Haab dates
`daysSinceEpoch`Premium	number	`1876383`	Days since Mayan creation date (0.0.0.0.0)

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Plan	Per month	Credits	Mayan Calendar calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Compare all pricing tiers →

Call it from cURL — GET /v1/mayancalendar

No SDK to install — this is a plain HTTPS call to /v1/mayancalendar with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
2

curl "https://api.apiverve.com/v1/mayancalendar" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/mayancalendar-apiSource, issues and the examples this page is built from.ReferenceMayan Calendar API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/mayancalendarnpm APIVerve.API.MayanCalendarNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Node.js — GET /v1/mayancalendar

Install the Node.js SDK, then call the Mayan Calendar API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/mayancalendar

Node.js

const res = await fetch("https://api.apiverve.com/v1/mayancalendar", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/mayancalendarThe published Node.js client, versioned and signed.GitHubapiverve/mayancalendar-apiSource, issues and the examples this page is built from.ReferenceMayan Calendar API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

APIVerve.API.MayanCalendarNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — GET /v1/mayancalendar

No SDK to install — this is a plain HTTPS call to /v1/mayancalendar with your key in the x-api-key header. Swap in a real key and it runs as-is.

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/mayancalendar",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

Also published for

@apiverve/mayancalendarnpm APIVerve.API.MayanCalendarNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from C# / .NET — GET /v1/mayancalendar

Install the C# / .NET SDK, then call the Mayan Calendar API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.MayanCalendar

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/mayancalendar");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.MayanCalendarThe published C# / .NET client, versioned and signed.GitHubapiverve/mayancalendar-apiSource, issues and the examples this page is built from.ReferenceMayan Calendar API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/mayancalendarnpm

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — GET /v1/mayancalendar

No SDK to install — this is a plain HTTPS call to /v1/mayancalendar with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/mayancalendar", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

Also published for

@apiverve/mayancalendarnpm APIVerve.API.MayanCalendarNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — GET /v1/mayancalendar

No SDK to install — this is a plain HTTPS call to /v1/mayancalendar with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/mayancalendar");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

Also published for

@apiverve/mayancalendarnpm APIVerve.API.MayanCalendarNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — GET /v1/mayancalendar

No SDK to install — this is a plain HTTPS call to /v1/mayancalendar with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/mayancalendar")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

Also published for

@apiverve/mayancalendarnpm APIVerve.API.MayanCalendarNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

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Mayan Calendar API

Try it — live request, no key required

About the Mayan Calendar API

What people use it for

Ways to call it

Other ways to use Mayan Calendar

Questions.

Request parameters — GET /v1/mayancalendar

Required

Authentication

Response — GET /v1/mayancalendar

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — GET /v1/mayancalendar

Resources

Also published for

Call it from Node.js — GET /v1/mayancalendar

Resources

Also published for

Call it from Python — GET /v1/mayancalendar

Resources

Also published for

Call it from C# / .NET — GET /v1/mayancalendar

Resources

Also published for

Call it from Go — GET /v1/mayancalendar

Resources

Also published for

Call it from PHP — GET /v1/mayancalendar

Resources

Also published for

Call it from Ruby — GET /v1/mayancalendar

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — Mayan Calendar API

Reference Data

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