About this tool
Birthday Countdown Calculator is a free, in-browser tool that counts down to your next birthday. Nothing is uploaded — it works out the date and the number of days left entirely on your device.
It takes the month and day of your birth date and builds this year's birthday. If that date is still ahead (or is today), it counts down to it; otherwise it rolls to next year's. The days remaining are the whole days from today to that birthday, the weeks are that figure divided by seven, and the age you will turn is the birthday's year minus your birth year. If today is your birthday it says 'Today!' instead of zero.
February 29 birthdays are handled gracefully: in common (non-leap) years there is no 29th, so the countdown targets March 1 and shows a note explaining the fallback. Pick your birth date and the days left, exact date, weekday and turning-age update instantly.
Frequently asked questions
Which birthday does the countdown target?
The next one. If this year's birthday is still in the future — or is today — that date is used; once it has passed, the tool automatically counts down to next year's birthday instead.
How are the days and weeks remaining calculated?
It measures the whole days from today's date to the next birthday, both taken at midnight, so the count is exact. Weeks are simply that number of days divided by seven and rounded down; on the day itself it shows 'Today!'.
What happens with a February 29 birthday?
In leap years the countdown targets the real February 29. In common years there is no 29th, so it falls back to March 1 and shows a note letting you know — you could also mark it on February 28 if you prefer.
Is my birth date stored or uploaded?
No. Everything is computed locally in your browser; your birth date is never sent to a server and nothing is saved.
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