Biorhythm Critical Days API

The dates a cycle crosses zero, marked single, double or triple

POST/v1/biorhythm/critical-days

1 credit · Secret key (test or live) · getBiorhythmCriticalDays

With 23 and 33 days the crossing can fall between two dates. A date is critical when a crossing falls between its start and the start of the next date. At most 366 days.

Request body

birth_date string (date) required
The date of birth. It is used for this response and not stored.
e.g. "1990-08-13"
from string (date) required
e.g. "1990-08-13"
to string (date) required
Inclusive. At most 366 days from from.
e.g. "1990-08-13"

No other fields are accepted.

Response

JSON { data, meta, warnings }, where data is:

from string (date) required
e.g. "1990-08-13"
to string (date) required
e.g. "1990-08-13"
count integer required
days array of object required
- date string (date) required
  e.g. "1990-08-13"
- days_since_birth integer required
- kind string required
  one of single, double, triple
- crossings array of object required
  Fields
  - cycle string required
    one of physical, emotional, intellectual
  - direction string required
    one of rising, falling
  - crossing_day number required
    Days since birth at the crossing. It can end in .5.
rule string required

Errors: 400, 401, 403, 404, 422, 429, 500. See error codes.

Example request

curl -X POST 'https://api.astrologics.in/v1/biorhythm/critical-days' \
  -H 'Authorization: Bearer al_test_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"birth_date":"1990-05-15","from":"2026-11-01","to":"2026-11-30"}'

Node.js

const res = await fetch("https://api.astrologics.in/v1/biorhythm/critical-days", {
  method: "POST",
  headers: { Authorization: "Bearer al_test_YOUR_KEY", "Content-Type": "application/json" },
  body: JSON.stringify({
    "birth_date": "1990-05-15",
    "from": "2026-11-01",
    "to": "2026-11-30"
  }),
});
console.log(JSON.stringify(await res.json(), null, 2));

Python

import json
import urllib.error
import urllib.request

body = {
    "birth_date": "1990-05-15",
    "from": "2026-11-01",
    "to": "2026-11-30",
}

req = urllib.request.Request(
    "https://api.astrologics.in/v1/biorhythm/critical-days",
    method="POST",
    headers={"Authorization": "Bearer al_test_YOUR_KEY", "Content-Type": "application/json"},
    data=json.dumps(body).encode(),
)
try:
    with urllib.request.urlopen(req) as res:
        print(json.dumps(json.load(res), indent=2, ensure_ascii=False))
except urllib.error.HTTPError as err:
    print(err.code, err.read().decode())

PHP

<?php
$ch = curl_init('https://api.astrologics.in/v1/biorhythm/critical-days');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_HTTPHEADER => ['Authorization: Bearer al_test_YOUR_KEY', 'Content-Type: application/json'],
    CURLOPT_POSTFIELDS => '{"birth_date":"1990-05-15","from":"2026-11-01","to":"2026-11-30"}',
    CURLOPT_RETURNTRANSFER => true,
]);
echo curl_exec($ch), PHP_EOL;

Example response

200 OK · 1,867 characters

{
  "data": {
    "from": "2026-11-01",
    "to": "2026-11-30",
    "count": 5,
    "days": [
      {
        "date": "2026-11-10",
        "days_since_birth": 13328,
        "kind": "double",
        "crossings": [
          {
            "cycle": "physical",
            "direction": "falling",
            "crossing_day": 13328.5
          },
          {
            "cycle": "emotional",
            "direction": "rising",
            "crossing_day": 13328
          }
        ]
      },
      {
        "date": "2026-11-14",
        "days_since_birth": 13332,
        "kind": "single",
        "crossings": [
          {
            "cycle": "intellectual",
            "direction": "rising",
            "crossing_day": 13332
          }
        ]
      },
      {
        "date": "2026-11-22",
        "days_since_birth": 13340,
        "kind": "single",
        "crossings": [
          {
            "cycle": "physical",
            "direction": "rising",
            "crossing_day": 13340
          }
        ]
      },
      {
        "date": "2026-11-24",
        "days_since_birth": 13342,
        "kind": "single",
        "crossings": [
          {
            "cycle": "emotional",
            "direction": "falling",
            "crossing_day": 13342
          }
        ]
      },
      {
        "date": "2026-11-30",
        "days_since_birth": 13348,
        "kind": "single",
        "crossings": [
          {
            "cycle": "intellectual",
            "direction": "falling",
            "crossing_day": 13348.5
          }
        ]
      }
    ],
    "rule": "A date is critical when a cycle crosses zero between its start and the start of the next date."
  },
  "meta": {
    "request_id": "req_example",
    "api_version": "v1",
    "engine_version": "2026.10.10",
    "mode": "live",
    "credits_charged": 1
  },
  "warnings": []
}

Try it

Test key (optional)

Leave empty to use the shared demo key (limited). Test keys only: never charged. Kept in this browser tab and sent through this site to the API. Create one

Body (JSON)

{
  "birth_date": "1990-05-15",
  "from": "2026-11-01",
  "to": "2026-11-30"
}

Biorhythm Critical Days API

Request body

Response

Example request

Example response

More in Biorhythm