Find a useful starting point
Choose a calculator for a quick answer or a guide for the reasoning behind it. The complete page list below includes our calculation method, contact details and privacy information.
Make a little more sense of time.
AgeUse brings simple date tools and thoughtful explanations together.
CalculatorsA date, a few days from now.
Add or subtract whole calendar days from a starting date.
CalculatorsYour age, down to the day.
Find the completed years, months and days between a date of birth and a date you choose.
CalculatorsSomething to look forward to.
Find the next birthday on or after your chosen date and count the days until it arrives.
About AgeUseQuestions, corrections and useful details.
Get in touch about an AgeUse page or calculation.
CalculatorsHow many days are in between?
Count calendar days between two dates, with a clear choice about including both endpoints.
DirectorySmall notes for everyday dates.
Plain-language guides to calendar arithmetic and a little planning.
Calendar guidesA little planning for a meaningful day.
Turn a birthday countdown into a simple, manageable plan.
Calendar guidesMonths do not all have the same shape.
How month lengths affect anniversaries and date arithmetic.
Calendar guidesWrite dates so they are easy to read.
A few small choices help prevent month-and-day mix-ups.
Calendar guidesA date is not a timestamp.
Why the tools count calendar dates without asking for a time zone.
Calendar guidesA year is more than 365 days.
Understand why calendar age and total days are different ways of describing the same span.
Calendar guidesAre you counting the gap or the dates?
One simple distinction explains many one-day differences between results.
Calendar guidesThe extra day, explained.
A short guide to February 29 and the Gregorian leap-year rule.
Calendar guidesGive a milestone a little context.
A useful personal timeline is more than a list of dates.
About AgeUseYour dates stay with you.
How AgeUse handles calculator inputs and ordinary website visits.
About AgeUseUsing the tools thoughtfully.
The scope and conventions of AgeUse calculators and guides.
DirectoryA few useful ways to count time.
Four simple calculators for ages, birthdays and the dates in between.