Next Birthday Calculator

A small, satisfying question: how long until your birthday, and what day of the week does it land on? This calculator counts the days to your next one, tells you the age you will turn, and names the weekday — which is usually the detail people actually want, because it decides whether the plan is a dinner or a weekend.

How to use it

1. Enter your date of birth.
2. Read the days remaining and the age you will turn.
3. Check the weekday before you start planning.

Examples

• Born 15 June 1995: on 1 January 2026 that is 165 days away, turning 31, falling on a Monday.
• If the birthday has already passed this year, the count rolls forward to next year automatically.

Frequently asked questions

How many days until my birthday?

Enter your date of birth and the calculator counts forward to the next occurrence. If this year's has already passed, it rolls to next year rather than returning a negative number. The count is in whole days from today, so it changes at midnight rather than at the hour you were born.

What happens if I was born on 29 February?

In a non-leap year there is no 29 February, so most calendars and legal conventions treat 1 March as the anniversary — some treat 28 February. This calculator follows the date arithmetic of your browser, which rolls to 1 March. It is worth knowing that the convention itself is not universal.

Which day of the week will my birthday fall on?

The calculator names it. Because a common year is 365 days and 52 weeks is 364, a birthday shifts forward one weekday each year, and two after a leap day — which is why the same date wanders through the week over time.

Does this use my local time zone?

It uses whole calendar dates rather than instants, so time zone makes no practical difference to the count. Nothing you enter is sent anywhere — the whole calculation happens in your browser.