About Age & Date
Age & Date is an independent project publishing eight free date calculators on the web and on Android. No accounts, no paywall, no data collection — every calculation runs on your own device.
Who makes this
Age & Date is built and maintained by BeFunnyStudio, a small independent software studio. It is a one-person operation: there is no editorial team, no investors and no sponsored placements. When something on the site is wrong, there is exactly one person to tell, and they can be reached directly at contact@befunnystudio.com or through the contact page.
The project started from a small irritation: almost every date calculator on the web either wraps a trivial subtraction in three layers of advertising, or gets the arithmetic subtly wrong — usually by treating a month as 30 days. The aim here was to get the calculation right first, explain it openly, and keep the interface out of the way.
How the calculations work
Everything on the site is powered by a single date engine: ten pure functions covering age, date difference, weekday, countdown, business days, world clocks, meeting windows, historical age and pregnancy dating. Two design decisions shape all of it.
Calendar units are counted, not divided. Whole years are counted first, then whole months, then the remaining days — borrowing the real length of the preceding month rather than assuming 30. This is the convention used by civil registries, by contract law in most jurisdictions and by the ISO 8601 duration model, and it is why an age from this site matches the one on official paperwork. Dividing a day count by 365.25 gives a different, usually wrong answer.
Date-only arithmetic is anchored to UTC. A birth date is a calendar date, not an instant, so it should mean the same thing whether you open the page in Los Angeles or in Auckland. Only genuinely live values — the seconds-lived counter, countdowns, world clocks — use the current instant, and all of them are driven by a single shared one-second timer so they never drift apart from one another.
There is more detail on each method on the individual calculator pages and in the guides.
How accuracy is verified
The engine exists twice — once in TypeScript for the web, once in Dart for the Android app — written from a single shared specification. Both implementations are covered by mirrored test suites: the same inputs, the same expected outputs, asserted line for line on both sides. A figure that differs between the two is treated as a bug, not a platform difference.
Reference tables — zodiac date ranges, fetal growth weeks, public holiday calendars, time zone metadata, historical figures — live in a single source file and are generated into both applications, so the web and the app can never fall out of step on the underlying data.
That said, no calculator is a substitute for professional judgement. The pregnancy calculator does not replace antenatal care; the business days calculator does not replace legal advice on a filing deadline. The terms of use set this out plainly.
How the site is funded
Age & Date is free and paid for entirely by display advertising — Google AdSense on the web, Google AdMob in the Android app. There is no premium tier and no feature is held back behind one.
Advertising imposes rules on how the site is built, and we hold to them deliberately: every ad slot carries a visible “Advertisement” label, sits in its own distinct container, and is never styled to blend into the results or the editorial text. Slot heights are reserved before the ad loads so nothing jumps under your cursor. No ad is ever placed adjacent to a primary button, and no calculation is ever gated behind one.
We do not run sponsored content, affiliate links or paid placements, and no advertiser has any influence over what the guides say. Ads are not personalised unless you consent through Google's certified consent message. Details are in the privacy policy.
Privacy by construction
The site has no backend. It is a set of static files with a few kilobytes of JavaScript, so the dates you type are processed in your browser and are never transmitted to us — we could not read them if we wanted to. Preferences such as your theme choice or the time zones you added are stored in your browser only. Nothing about how the site works requires an account, and none is offered.
The Android app
The same eight calculators are published as a free Android app under the package com.ageanddate.app, built with Flutter and following Material 3 conventions. It runs the mirrored engine described above, works offline, and adds two things the web cannot do well: a local notification when a countdown reaches its target, and native date pickers. Otherwise the numbers are identical to the day.
Corrections
If a figure looks wrong, a holiday calendar is out of date, or a guide has aged badly, please say so. Time zone rules and public holiday calendars in particular change by legislation several times a year, and a report from someone on the ground is usually how we find out first. Every guide shows the date it was last reviewed.