Find the number of days between two dates, or add and subtract days from a date. Perfect for deadlines, countdowns, due dates and planning.
Use the first box to find the days between two dates, and the second box to add or subtract days from a date. Pick the dates from the calendar and click Calculate.
A date calculator answers two questions people ask all the time: how many days are there between two dates, and what date will it be in 30 days, or 90 days, from today? Counting days by hand means flipping through a calendar and adding up months of different lengths, which is slow and easy to get wrong. This free date calculator does it in one second. Pick two dates to see the days between them, or pick a date and add or subtract days to find the new date.
Dates matter for deadlines, exams, deliveries, pregnancies, visas and holidays. A student wants to know how many days are left before an exam. A worker wants to know the last date to submit a form. A traveller wants to know what date it will be 14 days after arrival. A shopkeeper wants to know when a 30-day payment is due. This calculator handles leap years correctly, so the answer is right even across February in a leap year.
Take the dates 1 January 2026 and 10 November 2026. The days between them are 313 days, which is about 44.7 weeks. Another example: add 30 days to 10 November 2026 and you get 10 December 2026. Subtract 14 days from 10 November 2026 and you get 27 October 2026. Try your own dates above: pick a start date and an end date for a holiday, or add 90 days to today to find a deadline.
Dates are stored as a count of days, so the calculator simply subtracts one date from the other and divides by the number of milliseconds in a day. Adding days works the same way in reverse: the calculator adds the days to the starting date and works out the new day, month and year. Leap years add an extra day on 29 February, and the calculator includes it automatically. Months have different lengths — 31 days, 30 days, or 28 or 29 days for February — and the calculator handles all of them.
Count from the right start date. If you want days left before an exam on 10 November, start from today, not from yesterday. Remember the end date counts. The result is the number of days between the two dates; if you need to include both end days, add one. Use it for deadlines. Add 30, 60 or 90 days to today to find payment and submission deadlines. Plan holidays backwards. Subtract the travel days from your return date to find the last day you can leave. Check leap years. Dates across February in a leap year have one extra day, so let the calculator do the work instead of guessing.
Count carefully across months and leap years. When you count days between two dates by hand, remember that months have different lengths and February has 29 days in a leap year. A quick check is to count the full months first and then the leftover days, or simply use the calculator above, which handles month lengths and leap years for you, including the extra day in February every four years.
Suppose today is 1 March 2026 and your exam is on 10 November 2026. How many days do you have to prepare? Enter 1 March 2026 as the first date and 10 November 2026 as the second date, and the calculator shows 254 days. That is about 8 months and 9 days, or about 36 weeks. Breaking a long countdown into weeks makes it easier to plan: 254 days is 36 full weeks, so you can plan 36 weekly study goals. Try the same calculation with your own important date.
Forgetting leap years. A period that includes 29 February has one extra day, so counting 365 days per year gives the wrong answer. Counting the start date twice. From 1 March to 10 March is 9 days, not 10, because you do not count both end dates. Mixing up day and month. Check whether your browser expects day first or month first before you type a date. Ignoring time zones. A date in one country can be a different date in another country at the same moment. Using 30 days for every month. Months have 28, 29, 30 or 31 days, so adding "one month" is not the same as adding 30 days.
Pro Tip: For project planning, count working days instead of calendar days: 254 calendar days is about 181 working days, because weekends take out roughly two days in every seven.
Note: This calculator counts calendar days using your device's calendar. It does not remove weekends or public holidays unless you do that yourself.
How many days are there between 1 January and 10 November 2026? There are 313 days between them, which is about 44.7 weeks. You can check it in the first box above.
What date is 30 days from 10 November 2026? It is 10 December 2026. Enter the date and 30 in the second box to see it.
Does the calculator handle leap years? Yes. Leap years add 29 February, and the calculator includes that extra day automatically when the dates cross it.
Can I count days in the past? Yes. Pick an earlier end date and the calculator shows the number of days as a negative number, with the absolute count beside it.
What is the difference between calendar days and working days? This calculator counts calendar days, including weekends. Working days are usually Monday to Friday only, so 30 calendar days is about 22 working days.
Is this date calculator free? Yes, it is completely free, with no sign-up and no limit on how many dates you calculate.
How many days are there between two dates? Subtract the earlier date from the later date. This calculator does it for you, including leap years, so you do not have to count month by month.
What date is 100 days from today? Use the add-days part of the calculator: enter today's date and add 100 days. The result is the date 100 days later.