Free online tool
Birthday Countdown
Find out how many days remain until the next birthday and which day of the week it lands on.
A birthday countdown is useful for party planning, travel arrangements, invitations, and answering the very important question: how many sleeps are left?
How to use it
- Enter the original birthday, including the year.
- The calculator finds the next occurrence after today.
- Use the result to plan reminders, invitations, or a celebration.
Good to know
The countdown is based on your device’s local calendar date.
No birthday information is saved or sent to the server.
Behind the answer
How this calculator works
The tool takes the birthday's month and day and places them in the current calendar year. If that date has already passed, it moves the birthday to the following year, then calculates the number of calendar days between today and that date.
For a February 29 birthday during a non-leap year, the tool uses February 28. Families and legal systems sometimes use March 1 instead, so choose the convention appropriate to your situation.
Worked example
If today is October 1 and the birthday is October 21, the countdown is 20 days. If the birthday was September 21, the next occurrence is in the following year.
Assumptions and limitations
- The result follows the local date reported by the device.
- It counts calendar-day boundaries rather than exact 24-hour periods.
- February 29 handling is a planning convention, not legal advice.
Common questions
Is today counted as a full day?
No. A birthday occurring today displays as today rather than one day away.
Why include the original birth year?
It lets the same date field describe the birthday unambiguously, although the countdown primarily uses its month and day.