Pick your birth month and day to see how many days are left until your next birthday, plus its date and weekday. Add your birth year to see the age you will turn.
Count the days to your birthday
How the birthday countdown works
The birthday countdown measures whole calendar days from today to the next occurrence of your birth month and day. It also shows the full date, weekday, and the age you will reach, which can be useful for invitations, travel planning, milestone celebrations, or simple curiosity. The answer updates as soon as you change the month, day or year, and your last entry is saved in this browser so the countdown is ready the next time you visit.
What happens on your birthday?
If today's local calendar date matches the entered month and day, the result displays “Happy birthday!” and shows zero days remaining. The calculation uses the date and time settings on your device.
February 29 birthdays
People born on February 29 only see their exact birth date in leap years, so leap-day birthdays need a convention in non-leap years. JavaScript calendar behavior can roll February 29 into early March when that date does not exist. Legal and cultural birthday rules vary by location, so confirm the applicable rule for eligibility or official deadlines.
The countdown is intended for planning and entertainment. For an exact age broken into years, months and days, use the chronological age calculator.
What does “days until my birthday” count?
The result counts date boundaries between today and your next birthday. It is a whole-calendar-day countdown, so it can say one day even when fewer than 24 hours remain. If your birthday is today, it shows zero days. Time zones matter: the page uses the calendar date configured on your device, which is useful when planning in your own location.
Examples of the next birthday rule
If today is June 1 and your birthday is June 10, the countdown is nine calendar days. If your birthday was May 10, the tool chooses May 10 next year. Adding your birth year also lets it calculate the age you will turn at that next occurrence. You can use it for invitations and reminders without doing mental subtraction across month or year boundaries.
For a birthday on February 29, our current countdown follows the browser calendar rollover in years without February 29, which places the observed date on March 1. If you use a February 28 convention, or need a legal age or eligibility date, apply the relevant local rule instead of this planning countdown.
Birthday countdown example
Suppose someone was born on July 4, 1990 and checks the countdown on September 30, 2026. Their 2026 birthday has already passed, so the next one is July 4, 2027.
Days left in 2026 after September 30: 92 (all of October, November, and December).
Days in 2027 up to and including July 4: 185.
Total: 92 + 185 = 277 days until the birthday, or 39 weeks and 4 days.
July 4, 2027 is a Sunday, and 2027 − 1990 means they will turn 37. The same method works for any date: count the remaining days in the current month and year, then add the days into the birthday month.
Ways to use a birthday countdown
Party and travel planning: know how many weeks you have to book a venue, send invitations, or arrange time off.
Milestone birthdays: track the run-up to an 18th, 21st, 30th, 50th, or 100th birthday.
Gift timing: order in time for shipping, especially when the birthday falls on a weekend.
Kids' excitement: children often ask "how many sleeps until my birthday?"; the day count answers that directly.
Using the birthday countdown result
You can calculate a countdown for yourself, a family member, or a friend. Only the month and day are needed to find the next birthday; the year is needed only to show the age the person will turn. If you are planning a party, check the result again after travel across time zones because the local date on your device may change.
The weekday is derived from the next occurrence of the birthday, not from the original birth year. This helps when choosing a weekend celebration or deciding when to send an invitation. The countdown is recalculated from today's date every time the page opens, so a returning visit always shows the current number of days remaining. Save the date shown in the result when planning with others.
A birthday countdown is different from an age calculator. The countdown looks forward to one recurring calendar date; an age calculator looks backward from today to the original birth date. To find how old someone was or will be on a particular day, use the age on date calculator. To see your whole life so far as a single number, the days alive calculator counts every day since you were born.
Birthday countdown FAQ
How many days until my birthday?
Choose your birth month and day in the countdown at the top of this page. It shows the number of calendar days from today to your next birthday straight away, along with its date and weekday. The page remembers your birthday on this device, so next time the answer appears as soon as the page opens.
How many weeks until my birthday?
Divide the days remaining by seven. The countdown does this for you and shows the result as whole weeks plus leftover days, for example 45 days is 6 weeks and 3 days.
Does the birthday countdown include today?
No. The countdown counts calendar days from today to your birthday, so today is not counted and the birthday itself is the last day reached. If today is June 1 and your birthday is June 10, the answer is 9 days. On your birthday the countdown shows 0 days.
How does the countdown handle a February 29 birthday?
In leap years the countdown uses February 29. In years without February 29 it follows the browser calendar rollover and counts to March 1. If you celebrate on February 28, or need a legal age or eligibility date, apply the rule that applies where you live.
Does the number of days until my birthday include weekends?
Yes. The countdown counts every calendar day from today, including Saturdays, Sundays and public holidays. It is not a working-day count.
Why is my countdown one day off?
The calculator uses the date on your device. If your device clock or time zone is wrong, or you are counting for someone in a different time zone near midnight, the result can differ by one day.
