Biorhythm API
Three cycles counted from the date of birth: the day's values, a chartable range, critical days, phases and two people's distance. Arithmetic, with the sources and the evidence stated.
| Operation | Credits | Key |
|---|---|---|
POST /v1/biorhythm/readingThe three cycles on a date, with their state, trend, next critical date and meaning | 1 | secret |
POST /v1/biorhythm/forecastThe three values for each day of a range, ready to chart | 1 | secret |
POST /v1/biorhythm/critical-daysThe dates a cycle crosses zero, marked single, double or triple | 1 | secret |
POST /v1/biorhythm/compatibilityHow far two people's cycles sit apart, scored for each cycle | 1 | secret |
POST /v1/biorhythm/phasesWhere each cycle is: its half, when that half began and ends, and the next peak and trough | 1 | secret |
POST /v1/biorhythm/dailyA short daily summary with the coming week's values | 1 | secret |
Example: The three cycles on a date, with their state, trend, next critical date and meaning
POST /v1/biorhythm/reading · 200 OK
{
"data": {
"date": "2026-11-02",
"days_since_birth": 13320,
"cycles": [
{
"id": "physical",
"name": "Physical",
"period_days": 23,
"value": 73.1,
"state": "positive",
"trend": "rising",
"day_in_cycle": 3,
"next_critical": "2026-11-10",
"meaning": "The physical cycle is in its upper half, which biorhythm charts read as more energy and stamina."
},
{
"id": "emotional",
"name": "Emotional",
"period_days": 28,
"value": -97.5,
"state": "negative",
"trend": "falling",
"day_in_cycle": 20,
"next_critical": "2026-11-10",
"meaning": "The emotional cycle is in its lower half, which biorhythm charts read as a quieter or more sensitive mood."
},
{
"id": "intellectual",
"name": "Intellectual",
"period_days": 33,
"value": -75.6,
"state": "negative",
"trend": "falling",
"day_in_cycle": 21,
"next_critical": "2026-11-14",
"meaning": "The intellectual cycle is in its lower half, which biorhythm charts read as a time for review over new work."
}
],
"critical_today": [],
"note": "Biorhythm is a tradition of counting days from birth. Controlled studies have not found that it predicts events, so read this for interest and not for decisions."
},
"meta": {
"request_id": "req_example",
"api_version": "v1",
"engine_version": "2026.10.10",
"mode": "live",
"credits_charged": 1
},
"warnings": []
}