Age Calculator API

Exact age in years, months and days on a given date, with totals in days and weeks and the next birthday.

POST /api/v1/tools/age-calculatorMCP age_calculatorTime & Date

Calculate exact age in years, months and days from a date of birth, plus total days and weeks, the weekday you were born and days to your next birthday.

Input

Send these as a JSON object. Unknown fields are rejected.

birthDate: Date of birth as YYYY-MM-DD. (string, up to 10 characters, required)
asOf: Date to calculate the age on, as YYYY-MM-DD. Defaults to today (UTC). Someone born on 29 February has their birthday on 28 February in common years. (string, up to 10 characters)

Try it in the browser JSON Schema Get an API key

curl https://pithlab.com/api/v1/tools/age-calculator \n  -H "Authorization: Bearer $PITHLAB_KEY" \n  -H "Content-Type: application/json" \n  -d '{"birthDate":"1990-05-15","asOf":"2026-10-20"}'

Example response

{
  "ok": true,
  "result": {
    "years": 36,
    "months": 5,
    "days": 5,
    "totalMonths": 437,
    "totalDays": 13307,
    "totalWeeks": 1901,
    "remainderDays": 0,
    "bornOnWeekday": "Tuesday",
    "birthdayToday": false,
    "nextBirthday": "2027-05-15",
    "nextBirthdayWeekday": "Saturday",
    "daysToNextBirthday": 207,
    "nextAge": 37,
    "text": "Age on 2026-10-20: 36 years, 5 months, 5 days (13,307 days)"
  }
}