Personal Year Number API

Only a birthdate

curl -X POST https://simplenumerologyapi.com/v1/cycles \
  -H 'X-API-Key: nk_…' \
  -H 'content-type: application/json' \
  -d '{"birthdate":"1990-03-12","date":"2026-10-28","years_ahead":3}'

{
  "object": "cycles",
  "birthdate": "1990-03-12",
  "date": "2026-10-28",
  "age": 36,
  "universal_year": 1,
  "universal_month": 2,
  "universal_day": 3,
  "personal_year": 7,
  "personal_month": 8,
  "personal_day": 9,
  "current_pinnacle":   {"stage": 2, "number": 4, "from_age": 30, "to_age": 38},
  "current_challenge":  {"stage": 2, "number": 2, "from_age": 30, "to_age": 38},
  "current_life_cycle": {"stage": 2, "number": 3, "from_age": 30, "to_age": 56},
  "upcoming_personal_years": [
    {"year": 2027, "personal_year": 8},
    {"year": 2028, "personal_year": 9},
    {"year": 2029, "personal_year": 1}
  ]
}

No name is needed, so you can show a forecast on the first screen of your onboarding, before you ask for anything else.

What each number is for

Send the user’s local date

date defaults to today in UTC. A user in Sydney opening your app in the morning is already on the next day, so send the date from their device or profile time zone. Every personal day is then right where the user is.

The answer depends only on the birthdate and the date, so one call per user per day is all you need: cache the response until midnight in their time zone.

Frequently asked questions

How is the personal year number calculated?

The birth month and day are added to the current universal year and reduced to a single digit. The API returns it as personal_year, along with the personal month and day built on top of it.

Can I get personal year numbers for future years?

Yes. Set years_ahead to any number from 0 to 10 and the response lists the personal year for each of the coming years.

Does the cycles endpoint need a name?

No. It needs only a birthdate, and optionally the date to calculate for.

How many requests does a daily forecast use?

One per user per day if you cache the response until the user’s midnight. On the free plan that covers three users with a daily check-in; Starter covers more than 300.