Editorial standards
These are the rules we hold ourselves to. They exist so you can judge how much weight to put on anything published here.
Who writes this
Content on ExactAge is researched and written by the ExactAge editorial team and reviewed before publication. Where a topic touches law, medicine or veterinary practice, we describe general conventions and point you to the source that actually governs, rather than substituting for professional advice.
How the calculators are built and checked
Correct date arithmetic is harder than it looks, and most errors in date tools come from a small number of well-known traps. We test against all of them:
- Month-end transitions — 31 January to 28 February, 31 March to 30 April, and similar cases where a target day does not exist.
- Leap years and century years — including 1900 and 2100, which are divisible by 4 but are not leap years.
- 29 February birthdays — in both leap and common years.
- Daylight saving transitions — every date is anchored at midday so a clock change cannot move it across a day boundary.
- Date parsing — dates are read component by component rather than through the browser's default parser, which treats plain date strings as UTC and can land a day early.
The core date functions are covered by an automated test suite, and results are cross-checked against an independent implementation written separately from the code being tested. Every calculator is checked in a real browser at phone, tablet and desktop widths before release.
Where more than one answer is defensible
Some date questions genuinely have more than one correct answer. The clearest example is what "one month after 31 January" means. We do not hide these choices: we pick the convention that matches standard practice, state plainly that we have picked it, and show worked examples of how it behaves at the edges.
If our figure differs from another tool's, comparing total-day counts will usually show the difference is a convention rather than an error. Where it is not, we want to hear about it.
Accuracy and corrections
We correct errors rather than quietly editing around them. If you find something wrong — in a calculation or in a guide — email hello@getexactage.com with enough detail to reproduce it. Corrections to substantive points are noted on the page.
Guides are reviewed when the underlying facts change. Age reckoning is a live example: South Korea standardised on international age in 2023, and our guide to age around the world was updated accordingly.
Independence and advertising
ExactAge is free and funded by advertising served through Google AdSense. Advertising pays for hosting and nothing else. We do not accept payment for coverage, for links, or for placement in our guides, and we do not publish sponsored posts or guest posts. No advertiser sees an article before it is published.
Where we link to an external source, it is because we think it is useful. We use no affiliate links.
What we will not publish
- Text copied from other sites. Everything here is written from scratch.
- Medical, legal or financial advice dressed up as general information.
- Claims about astrology's predictive power. We describe how the systems define themselves, which is a factual matter, and stop there.
- Invented precision — figures presented as exact when they are estimates. Our pet age calculator says plainly that it is an approximation.
Privacy
No calculator on this site transmits what you type. There is no account system and no database of user input. The full position is in our privacy policy.
Contact
Corrections, questions and suggestions: hello@getexactage.com, or via the contact page.