Birthday Countdown

Enter a birth date and the page shows exactly how long until the next birthday: days, hours, minutes and seconds, updating live, plus the day of the week it falls on and the age you (or they) will turn. The date is saved in this browser, so the countdown is waiting whenever you come back. On the day itself the page celebrates with confetti and switches to counting down to the following year. Several birthdays can be saved and switched between, which makes the page a simple reminder board for family and friends.

The countdown is calculated in your device's time zone, to midnight at the start of the birthday. A birthday on 29 February is celebrated on 1 March in non-leap years by convention (and by law in most countries for age-related purposes), and the countdown follows that rule. The "day of the week" line answers the most common follow-up question: a birthday moves forward one weekday each year, two after a leap day, so a Tuesday birthday this year is a Wednesday next year unless 29 February intervenes.

For the exact current age in years, months, days and even minutes, the age calculator does the sum in the other direction; the two pages share their arithmetic.

• Gift and card reminders. Note the day-of-week and the days remaining; anything under a week is a prompt to post the card.
• Party planning. Count backwards: invitations six weeks out, venue and cake two weeks out, shopping three days out. The date calculator gives the dates.
• Milestones. Save the 18th, 30th, 50th or 100th birthday of someone important and share the page.
• Classrooms. Teachers display the next birthday in the class on a screen; a visible countdown is a small thing that children enjoy.

For non-birthday events with a name and a months/weeks breakdown, the countdown to date page is the general version; for a plain countdown, the countdown.