How many seconds?
A typical year has 31,536,000 seconds (365 days). Leap years add a day—bumping that to 31,622,400 seconds. That’s a lot of ticking!
Big numbers
Birthday Countdown — Live Big Digits
Inputs
Countdown
Set your date of birth to begin.
—
Days
—
Hours
—
Minutes
—
Seconds
Next birthday: — · You’ll turn —
5 Fun Facts about Birthday Countdowns
Who celebrates first?
Birthdays arrive earlier for people near the International Date Line (like parts of Kiribati) and last for folks near it on the other side (like Baker Island). Time zones make parties chase the Sun!
Time zones
Leap-day birthdays
If you were born on Feb 29, non-leap years don’t have your exact date. Many celebrate on Feb 28 or Mar 1 — this tool’s default treats it as Feb 28.
Leap logic
Midnight matters
The countdown targets the moment your birthday starts (00:00 local time). You don’t need to wait for the party—midnight is the milestone!
Start of day
Longer or shorter birthdays?
With Daylight Saving Time, some birthdays are 23 hours long and others 25 (when clocks change). Your special day can literally stretch—or shrink—by an hour.
DST quirks
How it works
This birthday countdown is a simple way to see exactly how long it is until your next birthday. It turns your date of birth into a live countdown timer, showing the time left in days, hours, minutes, and seconds. Whether you are planning a party, tracking a milestone, or just curious, it gives you an easy, friendly answer to the common question, "How many days until my birthday?"
The concept is straightforward: the calculator looks at today's date, finds your next birthday on the calendar, and measures the time between now and that date. Because months have different lengths and leap years add an extra day, the tool uses real calendar rules instead of rough averages. If your birthday falls on February 29, it is treated as February 28 in non-leap years by default, so you still get a consistent yearly countdown.
To use it, pick your birth day, month, and year. The countdown starts immediately and updates every second. You will also see the calendar date of your next birthday and the age you will turn. If you want to reset, use the Clear button. If you want to share the countdown with family or friends, tap "Copy sharable link" to create a link that includes your date of birth, so the same birthday countdown opens on another device.
This tool is useful for more than parties. It can help with planning travel around a birthday, setting reminders for important age milestones, or double-checking timelines for school, work, or benefits that depend on your exact age. Parents can use it to track a child's upcoming birthday, and teams can use it for fun office celebrations. Because the calculator runs in your browser, everything stays on your device and results appear instantly.
Tip: Share the countdown with friends using the "Copy sharable link" button — it encodes your DOB in the URL.