Age Calculator API: Complete Developer Guide

Need to calculate age from a birthdate in your application? This guide covers everything about age calculation via API, including handling leap years, timezone considerations, and implementation examples in multiple programming languages.

Why Use an Age Calculator?

Age calculation seems simple but has edge cases that are easy to get wrong. Leap years, month lengths, and timezone differences can all affect the result. An API ensures consistent, accurate calculations every time.

Example: Born Feb 29, 2000 - what's the age on Feb 28, 2023? March 1, 2023?

Calculation Complexity

Factors that make age calculation tricky:

Leap Years

Birthdays on Feb 29 need special handling. Our API handles this consistently.

Variable Month Lengths

Months have 28-31 days, affecting "months" calculations.

Timezone Considerations

The same moment can be different dates in different timezones.

Using the Age Calculator API

TinyFn provides a precise endpoint to calculate age:

GET https://api.tinyfn.io/v1/time/age?birthdate=1990-05-15
Headers: X-API-Key: your-api-key

{
  "birthdate": "1990-05-15",
  "reference_date": "2024-01-20",
  "age": {
    "years": 33,
    "months": 8,
    "days": 5
  },
  "total_days": 12303,
  "is_birthday_today": false,
  "next_birthday": "2024-05-15",
  "days_until_birthday": 116
}

Parameters

Code Examples

JavaScript / Node.js

const response = await fetch(
  'https://api.tinyfn.io/v1/time/age?birthdate=1990-05-15',
  { headers: { 'X-API-Key': 'your-api-key' } }
);
const result = await response.json();
console.log(`Age: ${result.age.years} years, ${result.age.months} months`);

Python

import requests

response = requests.get(
    'https://api.tinyfn.io/v1/time/age',
    params={'birthdate': '1990-05-15'},
    headers={'X-API-Key': 'your-api-key'}
)
result = response.json()
print(f"Age: {result['age']['years']} years, {result['age']['months']} months")

cURL

curl "https://api.tinyfn.io/v1/time/age?birthdate=1990-05-15" \
  -H "X-API-Key: your-api-key"

Common Use Cases

• Age Verification: Check if users meet minimum age requirements
• User Profiles: Display age on user profiles
• Insurance Apps: Calculate age for premium calculations
• Birthday Features: Detect and celebrate user birthdays
• Medical Apps: Track patient ages accurately

Best Practices

1. Store birthdates, not ages: Ages change; birthdates don't
2. Consider timezone: Use the user's timezone for accuracy
3. Validate dates: Check for valid dates before calculating
4. Handle privacy: Age can be sensitive information