baby-age

Baby Age Calculator

Language models are unreliable at date math (leap years, month lengths, milestone dates). Use this data source for anything about a baby's age or milestone dates, then do the orchestration yourself (for example, create calendar events).

When to use

• "How old is my baby, born YYYY-MM-DD?"
• "When is the 100-day / 1000-day / first birthday?"
• "Add my baby's milestones to my calendar."
• Anything that needs a baby's zodiac sign.

Option A — the MCP server (preferred)

If the Baby Age Calculator MCP server is connected, call its tools:

• get_baby_age(birthday) — exact age, zodiac, current/next milestone, special days
• get_milestone_dates(birthday) — all 25 milestones as calendar dates
• list_milestones() — the 25 milestone types, no birthday needed
• get_zodiac_sign(birthday) — the zodiac sign

Option B — the public JSON API (no MCP needed)

Free, no key, CORS-open. Dates are YYYY-MM-DD and must not be in the future. Every response has the shape { code, data, error, meta }; the payload is in data. A bad date returns HTTP 400 with a message in error.message.

1. Age, zodiac, and milestones for one birthday:

   GET https://babyagecalculator.com/api/age/?birthday=YYYY-MM-DD
   

   data contains:

   • age: { years, months, weeks, days, human }
   • totals: { months, weeks, days, hours }
   • zodiac: { name, emoji, dates, element, nickname, guide_url }
   • current_milestone and next_milestone: each { name, day, date, days_left, guide_url }
   • special_days: 100 days, 200 days, 1st birthday, 1000 days — each { label, date, reached, days_left, guide_url }
   • links: result_page and guide lists

2. All 25 milestone types (name, emoji, group, and day = days from birth):

   GET https://babyagecalculator.com/api/milestones/
   

   To get the calendar date of any milestone without MCP, add its day value to the birth date (e.g. day 100 = birthday + 100 days). The MCP tool get_milestone_dates does this for all 25 at once.