Build your Date & Age Calculator with AI in under 5 minutes

Build a date and age calculator that finds the time between two dates, your exact age, or adds and subtracts days, months, and years — with full year/month/day breakdowns. Everything runs in the browser.

How it works

Step 1

Describe your idea

Write a plain-text prompt describing what you want.

Step 2

AI builds it

FloopFloop generates production-ready code instantly.

Step 3

Deploy & go live

Your project is hosted on its own subdomain in minutes.

Why build with AI instead of hiring a developer?

	FloopFloop	Traditional developer
Time to launch	Under 5 minutes	2-8 weeks
Cost	From $0	$5,000 - $50,000+
Maintenance	Included	Ongoing retainer

What is a date & age calculator?

A date and age calculator answers the small calendar questions that come up constantly: how old am I exactly, how many days until the wedding, how long did that project run, what date is 90 days from today and what weekday is it. The canonical tools — the 'age calculator' and 'date duration calculator' results that top the search page — do three jobs: the difference between two dates, an exact age as of today, and adding or subtracting a span from a date. They look trivial, but two details separate a correct one from a wrong one. The first is the year/month/day breakdown: people want '25 years, 11 months, 21 days,' counted the way you'd count by hand, not a raw day total. The second is correctness on the edge cases — leap years, and month-ends where 'one month after January 31' should be the end of February, not a date that doesn't exist. A surprising number of tools also drift by a day because they do the math in local time, where a daylight-saving change can move a result across midnight.

Common features

Difference between two dates, broken into years / months / days
Totals: total days, total weeks, total months
Exact age as of today from a date of birth
Day of the week for any date (and the day you were born)
A countdown to the next birthday or anniversary
Add or subtract years, months, and days from a date
Correct leap-year handling (Feb 29)
Intuitive month-end math (Jan 31 + 1 month = Feb 28/29)
UTC-based math so daylight saving never shifts a day
Everything client-side; light and dark themes; inputs remembered

Real-world examples

How old am I, exactly?

Someone enters their birthdate and gets '25 years, 11 months, 21 days,' the weekday they were born, and a count of days until their next birthday.

Counting down to a date

A couple checks how many days, weeks, and months until the wedding by dropping the two dates into the difference mode.

Working out a deadline

A freelancer adds a 30-day notice period to a start date and sees both the end date and that it lands on a Tuesday.

Why FloopFloop fits date & age calculator projects

A date calculator is a tiny tool you want instant, ad-free, and accurate. FloopFloop ships the calculator you want — the modes you use, the breakdown you prefer, your own additions like business-day counting — on your own domain, with everything computed in the browser. The clean 'almanac' look that ships by default states the answer in plain language rather than burying it in a results table, and the whole thing is one prompt away from being whatever fits your need.

Try these prompts

Copy any prompt below and paste it into FloopFloop to get started.

Build a date and age calculator with three modes. Difference: pick two dates and show the gap as years, months, and days plus total days, weeks, and months, with the weekday of each date. Age: enter a birthdate and show the exact age as of today, the day of the week they were born, and a countdown to their next birthday. Add/subtract: take a date and add or subtract years, months, and days to get a new date and its weekday. Handle leap years and month-ends correctly (Jan 31 + 1 month = Feb 28), compute everything at UTC midnight so daylight saving never shifts a day, and read 'today' on the client so the first render is hydration-safe. Show a big plain-language answer card; keep it 100% client-side.

Create an age calculator like the ones that tell you 'you are 25 years, 11 months, and 21 days old.' Enter a date of birth, get the exact age plus total days lived and days until the next birthday. No sign-up, runs in the browser.

Build a 'days between two dates' calculator: two date pickers and a clear result in days, weeks, and months, plus the calendar breakdown. Add a dark theme.

Build a date math tool that adds or subtracts a number of days, weeks, months, or years from a starting date and tells me the resulting date and what day of the week it falls on — useful for deadlines and due dates.

Frequently asked questions

How is the age / difference calculated?

The way you'd count by hand: whole years first, then whole months, then the leftover days. So from 2000-06-15 to 2026-06-05 is 25 years, 11 months, 21 days — not just a pile of days. It also reports the totals (total days, weeks, months) for when you need a single number.

Does it handle leap years and awkward month-ends?

Yes — that's the part naive calculators get wrong. Leap days (Feb 29) are counted correctly, and month-end math is intuitive: adding one month to January 31 lands on the last day of February rather than spilling into March. A Feb-29 birthday's countdown rolls to Feb 28 in common years.

Why are the results sometimes off by a day in other tools?

Usually a timezone bug: doing date math with local time means a daylight-saving change can nudge a result across midnight. This tool computes everything at UTC midnight, so the day count is stable no matter where you are or when DST flips.

What can I use it for?

Working out your exact age or someone's age, counting down to a wedding, launch, or due date, finding how many days a project ran, or adding a notice period or deadline to a start date and seeing which weekday it falls on.

Is anything sent to a server?

No. Every calculation runs in your browser and your inputs are saved to localStorage only. The single outbound surface is the /api/health probe.

Related builders

Explore more categories

Tip Calculator

Build a browser-side tip calculator with preset percentages (15 / 18 / 20 / 22 / 25 + custom), people-stepper bill split, tax-aware mode, round-up toggle, and multi-currency support — wrapped in a vintage diner-receipt visual identity no other tip tool ships.

Ready to build?

Start building your project now — no coding required.

Generate this for me

Start Building