Whether you are waiting for a holiday, a due date, a wedding or the end of a semester, “how many days until…” is a question a calendar answers badly — you end up counting squares and losing track at month boundaries. This calculator does the subtraction for you. Pick the date, and it shows the days remaining, the same span in weeks and days, the number of working weekdays, and the total in hours.
How to use the days until calculator
- Choose the target date with the date picker — a birthday, deadline, trip or event.
- Read the result. The count starts from today’s date on your device, so the figure is always current.
- Check the extras. Weeks and days are handy for planning (“9 weeks and 2 days”), and the weekday count shows how many workdays you have before a deadline.
If the date is in the past, the calculator tells you how many days ago it was instead.
Days until formula
Weeks = ⌊ days ÷ 7 ⌋, remainder = days mod 7
Hours = days × 24
Behind the scenes each date is converted to a count of days since a fixed starting point (a “day number”), so month lengths and leap years take care of themselves. The difference of the two day numbers is the answer. Dates are treated as whole calendar days, so daylight-saving changes never shift the result by an hour.
Worked example: counting to Christmas
Today is October 15, 2026 and the target is December 25, 2026.
- Days left in October after the 15th: 31 − 15 = 16.
- All of November: 30.
- Days into December: 25.
- Total: 16 + 30 + 25 = 71 days, which is 10 weeks and 1 days, or 1,704 hours.
- Weekdays in that span: 51.
Days until popular dates (from October 15, 2026)
| Event | Date | Days | Weeks & days | Weekdays |
|---|---|---|---|---|
| Halloween | Saturday, October 31, 2026 | 16 | 2 wk 2 d | 12 |
| Thanksgiving (US) | Thursday, November 26, 2026 | 42 | 6 wk 0 d | 30 |
| Christmas Day | Friday, December 25, 2026 | 71 | 10 wk 1 d | 51 |
| New Year's Day | Friday, January 1, 2027 | 78 | 11 wk 1 d | 56 |
| Valentine's Day | Sunday, February 14, 2027 | 122 | 17 wk 3 d | 87 |
These values are counted from October 15, 2026; use the calculator above for today’s count.
Day of the year at the start of each month
If you know the day-of-year number of two dates you can subtract them directly. Leap years add one day after February 28.
| Month | Days | Day of year on the 1st (common year) | Day of year on the 1st (leap year) |
|---|---|---|---|
| January | 31 | 1 | 1 |
| February | 28 (29 in leap years) | 32 | 32 |
| March | 31 | 60 | 61 |
| April | 30 | 91 | 92 |
| May | 31 | 121 | 122 |
| June | 30 | 152 | 153 |
| July | 31 | 182 | 183 |
| August | 31 | 213 | 214 |
| September | 30 | 244 | 245 |
| October | 31 | 274 | 275 |
| November | 30 | 305 | 306 |
| December | 31 | 335 | 336 |
Counting conventions to be aware of
- Exclusive vs. inclusive. “Days until” normally excludes today. A three-day event from the 10th to the 12th spans 3 calendar days but is only 2 days after the 10th.
- Business days. Legal and shipping deadlines often count only working days; the weekday figure is a good starting point, then subtract holidays that apply to you.
- Time zones. The count uses your local calendar date, so a deadline in another time zone may roll over earlier or later.
Need the gap between two specific dates, or want to add days to a date? Use the Date Calculator. To plan by weeks, try the Weeks From Date Calculator calculator, and to find the date that lands a number of days ahead, use Days From Date Calculator.
Frequently asked questions
How many days until Christmas?
Enter December 25 of the year you want. Counting from October 15, 2026, there are 71 days until Christmas Day 2026. The calculator uses your device’s date, so it always counts from today.
Does “days until” include today?
No. It counts the midnight-to-midnight steps between today and the target, so tomorrow is 1 day away and today is 0. If you want to count both ends — for example the number of calendar days a trip covers — add 1.
Does it account for leap years?
Yes. February has 29 days in leap years such as 2028 and 2032, and the date arithmetic handles that automatically. Century years are leap years only when divisible by 400, so 2100 will not be one.
Can I count back from a past date?
Yes. If the date has already passed you will see how many days ago it was, along with the weeks and weekdays that have gone by.
What does the weekday count measure?
The number of Monday-to-Friday days from today up to, but not including, the target date. It does not remove public holidays, because those differ by country and employer.