Age and a guide to filings

From your date of birth, see typical windows for passports, visas, contracts, and other applications — including the days before and after. Recheck what the birthday itself actually marks.

Runs fully in your browser — dates stay on this device. Nothing you enter is sent anywhere.

Completed age as of today — a quick check before you open the given-date tab.

Completed age on an application, inspection, year-end, or posting date — the figure the form wants.

Weekday, ISO week, Japanese era, Western zodiac, the Chinese-zodiac animal, and the next birthday.

The birthday month and the months before and after it, with weekdays, weekends, and the main public holidays of the country you pick — a guide for when a counter might be open.

Crowding over these three months

A guide from leisure-season patterns and public holidays — not measured queue times.

The span between two people, two events, or two contracts.

First date
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Second date
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Estimate a date of birth from an age, or name the calendar day when a birth date turns N years.

From an age

Completed age

Date when it turns N years

Anniversary timeline

Enter a start date above to see the anniversary timeline.

Days to the next anniversary will appear here.

Tips

The Age That Goes on the Form

A passport, visa, contract, or inspection asks for completed age on that day — not a rounded year. Type the start date and the filing date; the years, months, and days are already there.

Leap Years Count Too

Completed age is not years times 365. Some years include a February 29 and some do not. Skip that and the age on a visa or inspection date slowly goes wrong. Real age follows the calendar, leap days included.

Names That Sit on a Date

Weekday, ISO week, Japanese era, Western zodiac, and the Chinese-zodiac animal — the same kind of field a form already prints.

Crowding Is Only a Guide

The three-month window includes a crowding sketch from leisure-season patterns and public holidays. It is not measured queue times. Opening hours still come from the form.

Common Use Cases

🛂

Passport and Visa Filing Day

Completed age on the day you lodge the application — the figure the form wants, not the age you say in conversation.

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Contract and Inspection Date

A lease, a medical exam, or a workplace checkup often keys off age on that calendar day. Set the filing date and read the completed years.

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Year-End and Secondment Day

Year-end close (31 December) or a tax-year date — 15 April in the US, 5 April in the UK — is just another filing date.

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A Window Around the Birthday

The birthday month and the months on either side, with weekends and the main public holidays of the country you pick. A guide for when a counter might be open — not a booking.

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The Gap Between Two Dates

The exact span between two people, two events, or two contracts, in years, months, and days — not "about four years apart."

Frequently Asked Questions

How do you calculate exact age?
Complete years, months, and days from the start date to the filing date. Each month's real length is used, and leap years are included. That is calendar age, not a 365-day approximation.
Does this handle leap years and February 29?
Yes. February 29 start dates are kept. In a common year the next anniversary is treated as March 1.
Can I see age on a visa or inspection date?
Yes. Open Age on a given date, enter the date of birth and the day of the application, inspection, or year-end close. The result updates as soon as both dates are in.
Why did other tabs fill in by themselves?
The date of birth is shared across tabs by default. A green tab was updated in the background. Uncheck "Use this start date on the other tabs" to keep dates separate. Find the date of birth does not take dates from the other tabs, but once it has an estimate it fills the age tabs that need a birth date.
Can I work backwards from an age to a date of birth?
Yes. Find the date of birth subtracts years, months, and days from a reference date. The same tab also names the calendar day when that birth date turns N years. Treat either result as a check — official filings still need an ID.
Why does the table stop at days?
The four-row table under the main answer restates the same span as years only, months only, weeks only, or days only. Hours and seconds are omitted on purpose. Do not add the rows together — they are alternative writings of one period.
What does When to file show?
Three months around the next birthday: the month before, the birthday month, and the month after, with weekends and the main national public holidays of the country you pick. A crowding guide for those months sits on this tab. It follows leisure-season patterns and public holidays — not measured queue times. State or city holidays are not listed.
Are the dates I enter sent to a server?
No. Dates stay in the browser. Nothing is uploaded. Last-used values may be saved only on this device.