Day Countdown

DateMath reads the current time from your device and counts the real time left until your own clock shows the date and time you picked, so the countdown reaches zero at that moment, and a daylight saving change in between adds or takes away its hour. The tiles show whole 24-hour days, then hours, minutes and seconds. The calendar-day line counts dates, the way you would on a wall calendar, so it changes at midnight; business days skip weekends and US federal holidays, with neither today nor the target day counted.

• Your device's local time. DateMath's countdowns read the current time from your device and count to the target in your own time zone. In the US, the standard time zones are set by 15 U.S.C. 261 and daylight saving time by 15 U.S.C. 260a (from 2:00 AM on the second Sunday in March to 2:00 AM on the first Sunday in November); your device applies them. Source: 15 U.S.C. 261, 15 U.S.C. 260a.
• US federal holidays. DateMath skips the 11 annual holidays of 5 U.S.C. 6103 on the days they are observed for federal employees, as the US Office of Personnel Management (OPM) lists them: a Saturday holiday on the Friday before, a Sunday holiday on the Monday after. Source: 5 U.S.C. 6103, OPM federal holidays.
• The Gregorian calendar. DateMath treats every date as a Gregorian date, with its leap-year rule: a year divisible by 4 is a leap year, except century years not divisible by 400, so 2000 had a February 29 and 2100 will not. Source: Gregorian calendar.

DateMath's date math is tested against more than 100 cases worked out by hand. Every worked example and table on the site is computed with the same code the calculators run, so a page and its calculator can't disagree.

The day countdown shows how long is left until a date and time you choose, as days, hours, minutes and seconds that tick down live. It works as a countdown date counter for a deadline weeks away and as a countdown clock for a time later today, and you can keep it open in a tab or on a second screen.

What you enter

• Event name (optional): shown above the countdown, such as "Countdown to Our wedding".
• Date and time: the moment to count down to. Leave the time at 12:00 AM to count to the start of that day.
• Presets: Midnight, Noon, Thanksgiving, Christmas, New Year and Halloween fill in the next one for you.

What you get

The tiles give the days, hours, minutes and seconds left. Under them, DateMath shows the weekday of the date, the calendar days to go with the same span in weeks and days, the total hours, and the US business days in between, which skip weekends and federal holidays. The copy-link button saves the countdown with its name, date and time, so a countdown timer to a date and time is one tap away on any device. Full screen fills a computer screen or a TV with the clock.

Midnight is 12:00 AM, the moment a new day starts, and noon is 12:00 PM. The Midnight preset counts down to the coming 12 AM, the start of tomorrow, and Noon to the coming 12 PM: today's until noon, then tomorrow's. For any other time, such as a countdown to 3:30 PM, 10 PM or 11 PM, keep today's date and set the time.

How many minutes till 12 AM? Take the minutes left in the current hour and add 60 for every full hour before midnight. At 9:47:15 PM, that is:

Minutes till midnight from common times

Thanksgiving Day is the fourth Thursday in November, one of the US federal holidays set by 5 U.S.C. 6103, so it always falls between November 22 and November 28. In 2026 it is Thursday, November 26, 2026, 37 days after October 20, 2026. The Thanksgiving preset counts down to the next one on your clock, and the table gives the dates ahead:

For a countdown to the holiday dinner rather than the start of the day, keep the date and set the time, such as 4:00 PM.

Any event with a date works: type its name, pick the date and time, and copy the link to keep it. Each countdown below starts at Tuesday, October 20, 2026, 9:00 AM on a New York clock.

Retirement countdown

A retirement on Wednesday, June 30, 2027, 5:00 PM is 253 calendar days away (36 weeks, 1 day), and the countdown clock shows 253 days, 8 hours. For the working days left, read the business days line: 172 business days lie in between, with weekends and US federal holidays left out. Your own vacation days are not known to the countdown, so subtract them yourself. DateMath counts the date only; it doesn't give retirement or benefits advice.

Wedding countdown

A wedding on Saturday, June 12, 2027, 4:00 PM is 235 days away, which is 33 weeks, 4 days. Name the countdown, copy the link and send it to the people you are planning with: each of them sees the same countdown, ticking on their own clock.

Disney and vacation trip countdowns

For a trip, count down to the departure rather than the day: a flight at 7:30 AM on March 14, 2027 is 144 days, 22 hours, 30 minutes away. A Disney countdown or any other vacation countdown works the same way; add the link to your phone's home screen and it opens like a countdown app.

Birthday countdown calculator

Enter the next birthday's date and a name, and copy the link to keep it like a birthday countdown app. The age calculator gives the date of the next birthday, the age it brings and the days until it from a date of birth.

The tiles count time: whole 24-hour days from this moment, then hours, minutes and seconds. The calendar-day line counts dates, as you would on a wall calendar, and changes at midnight. At 3:00 PM on February 5, 2027, the start of February 15, 2027 is 10 calendar days away, while the tiles show 9 days, 9 hours. Both are right; they answer "how many days until" in two ways.

Time zones and daylight saving time

The countdown reads the current time from your device and counts to the date and time on your own clock. A shared link therefore counts to the same clock time in each viewer's time zone, which suits birthdays, holidays and New Year. For an event set in one place, such as a launch at 9:00 AM Eastern, convert the time to your zone before you set it. The tiles count real time, so they drop by one second each second, also on the nights the clocks change, and still reach zero when your clock shows the target. A countdown across the fall change, when the clocks go back an hour, therefore shows one hour more than the clock difference, and one across the spring change one hour less. The calendar days and business days are dates, so they don't change.

A countdown of whole days is easier to picture in weeks, and the hours and minutes grow fast. The weeks and days line under the countdown does this for you:

To find the date a number of days from now rather than the time left until a date, use the date calculator; for a timer that counts down a length of time, such as 10 minutes, the countdown timer; and for the holiday pages, the Christmas, New Year and Halloween countdowns.