Weekday count excludes weekends only, not holidays.
About this tool
This calculator counts the days between two dates, or adds or subtracts a number of whole days from any starting date, using real calendar arithmetic, so leap years and varying month lengths are handled correctly without any manual adjustment. Everything runs in your browser.
How to use the Date Calculator
- Choose a mode at the top. Days between two dates is explained in the next section; the steps below are for Add or subtract days.
- Pick a starting date — defaults to today.
- Enter the number of days, or tap a quick preset.
- Choose before or after the starting date.
- Read the resulting date — it updates as you type.
Common use cases
- Finding a deadline that's a set number of days from today (like a 60-day or 90-day notice period)
- Working out a return, refund, or warranty date a fixed number of days after a purchase
- Calculating a due date, follow-up date, or reminder a set number of days out
- Checking what date it was a certain number of days before a known date
Worked example
A 60-day notice period given on Monday, January 4, 2027: choose Add or subtract days, set the Starting date to January 4, 2027, press the 60 days preset and leave Direction on After the starting date. The Result reads Friday, March 5, 2027. Adding "2 months" instead would give March 4, one day earlier, because January and February 2027 have 59 days between them.
Things to watch out for
In add or subtract mode, this calculator counts whole calendar days, not business days — if you need to exclude weekends or holidays from the count (common for legal or contractual deadlines), you'll need to adjust the result manually for those non-counted days. The starting date itself counts as day zero, so "1 day after" a date is the very next calendar day, matching how most people naturally think about counting days forward.
Counting dates correctly
Date math has traps. Months have 28 to 31 days, years have 365 or 366, and adding one month to January 31 has no single right answer, since February has no 31st. Decide whether you want to include the start date, because counting from Monday to Friday gives 4 days apart but 5 days if both ends count. For deadlines, contracts and legal periods, check which counting rule applies before relying on any calculator.
Worked examples with real dates
- 90 days after January 1, 2027 is Thursday, April 1, 2027. January has 30 days left after the 1st, February 2027 has 28 and March has 31, so 30 + 28 + 31 = 89 days reaches March 31, and one more day lands on April 1.
- 180 days after January 15, 2027 is Wednesday, July 14, 2027.
- 100 days before March 1, 2026 was Friday, November 21, 2025.
Why 90 days is not the same as 3 months
Months are 28 to 31 days long, so a deadline written in months and one written in days can fall on different dates. Three months after March 1, 2027 is June 1, but 90 days after March 1, 2027 is May 30, because March, April and May together have 92 days. If a contract, return policy or notice period says "90 days", count days; if it says "3 months", count calendar months. When the wording is unclear, ask whoever set the deadline.
How to count days by hand
- Work out how many days are left in the starting month after the start date.
- Add whole months, using each month's real length, until the next month would take you past your total.
- The remaining days give the day of the final month.
Month lengths follow the old rhyme, with February the exception: it has 29 days in a leap year. In the Gregorian calendar a year is a leap year if it is divisible by 4, except for century years, which must also be divisible by 400. So 2024 and 2028 are leap years, 2000 was, and 1900 and 2100 are not.
Inclusive or exclusive counting
This calculator counts the start date as day 0. Some rules count the first day as day 1, which moves the end date one day earlier. For example, a 10-day period that includes its first day, starting on the 1st, ends on the 10th, while "10 days after the 1st" is the 11th. To count the days between two dates you already know, switch the calculator to Days between two dates. For a live countdown to a future date and time, use the Countdown to a Date tool.
How to count the days between two dates
Choose Days between two dates at the top of the calculator, then pick a start date and an end date. By default the count includes the start date and stops the day before the end date, which is the same as subtracting one date from the other. That is the usual answer to questions like how many days until a trip or how many days since a purchase. Tick Include the end date when both the first and the last day should count, such as the length of a conference, a hospital stay or a run of work shifts. The result also shows the total as weeks plus days, the number of weekdays (Monday to Friday) and the number of weekend days.
Worked example: January 4 to March 31, 2027
- From Monday, January 4, 2027 to Wednesday, March 31, 2027 is 86 days: 27 days are left in January after the 4th, February 2027 has 28 and March adds 31.
- That is 12 weeks and 2 days, with 62 weekdays, counting January 4 through March 30.
- With Include the end date ticked, the answer becomes 87 days, or 12 weeks and 3 days, with 63 weekdays, because March 31, 2027 is a Wednesday.
Entering the two dates the other way round gives the same totals; the calculator puts them in order and tells you it did.
Why the count is done in UTC
The example span crosses March 14, 2027, when clocks in most of the United States move forward an hour for daylight saving time. Measured between local midnights, January 4 to March 31 is 86 days minus one hour, so code that divides the time difference by 24 hours and rounds down would report 85 days. This calculator treats each date as a whole calendar day in UTC, so a daylight saving change cannot shift the answer by a day. Leap years are handled the same way: February 1 to March 1 is 29 days in 2028 and 28 days in 2027.
Weekdays are not the same as business days
The weekday figure counts every Monday to Friday in the range and nothing else. It excludes weekends only, not holidays, so a public holiday, a regional holiday or a company closure day still counts as a weekday. For a business-day deadline, subtract any holidays that fall on a weekday in your range. Contracts, court rules and government forms can define their own counting method, so check the wording of the rule you are following.
Date calculator: two calculations in one tool
People use a date calculator for two different jobs. The first is days between two dates: enter a start and an end date and read the gap in days, weeks and weekdays. The second is add or subtract days from a date: enter a start date, a number of days and a direction, and read the resulting date with its weekday. Both run instantly, need no sign-up and never leave your browser.
| Question | Start date | Result |
|---|---|---|
| What date is 30 days after January 1, 2027? | January 1, 2027 | January 31, 2027 |
| What date is 90 days after January 1, 2027? | January 1, 2027 | Thursday, April 1, 2027 |
| What date is 100 days after January 1, 2027? | January 1, 2027 | Sunday, April 11, 2027 |
| How many days from January 1 to July 4, 2027? | January 1, 2027 | 184 days |
| How many days from January 1 to December 25, 2027? | January 1, 2027 | 358 days |
| How many days from January 15 to March 15, 2027? | January 15, 2027 | 59 days (8 weeks and 3 days) |
| How many days from February 1 to March 1, 2028? | February 1, 2028 | 29 days (2028 is a leap year) |
Turn days into weeks and months
Divide a day count by 7 to get weeks: 59 days is 8 weeks and 3 days. Months are harder because they vary from 28 to 31 days, so a fixed number of days never matches a calendar month exactly. For legal notices, lease terms and contracts, count the days first and then check how the document defines a month. For ages, use the Age Calculator; for a deadline that skips weekends, use the Business Days Calculator; and for the length of a shift or a clock-time gap, use the Elapsed Time Calculator.
Days between two dates
Pick Days between two dates, enter a start and an end date and read the gap. The tool counts from the start date up to, but not including, the end date unless you tick Include the end date. It shows the days, the same gap as weeks and days, and how many of those days are weekdays (Monday to Friday) and weekend days.
- March 1 to March 12, 2027: 11 days, which is 1 week and 4 days, with 9 weekdays and 2 weekend days.
- March 1 to June 1, 2027: 92 days, which is 13 weeks and 1 day, with 66 weekdays and 26 weekend days.
- January 15 to March 15, 2027: 59 days, which is 8 weeks and 3 days, with 41 weekdays and 18 weekend days.
Add days to a date
Pick Add or subtract days, enter a start date and a number of days (or press 30, 60, 90, 100, 180 or 365), and choose After the starting date. The result shows the full date and weekday.
- 45 days after March 15, 2027 is Thursday, April 29, 2027.
- 90 days after October 26, 2026 is Sunday, January 24, 2027.
- 180 days after June 30, 2027 is Monday, December 27, 2027.
Subtract days from a date
Choose Before the starting date to count backwards, for example to find a start date from a deadline.
- 30 days before March 1, 2027 is Saturday, January 30, 2027.
- 100 days before December 25, 2026 is Wednesday, September 16, 2026.
Weeks and months between dates
The calculator reports weeks and days, not months, because months have different lengths. For a rough month count, divide days by 30.4: 92 days is about 3 months, which matches March 1 to June 1. For exact years, months and days of a person’s age or an anniversary, use the Age Calculator or the Days Together Counter.
Business days between dates
This tool does not skip holidays. Its weekday figure counts every Monday to Friday, including public holidays. For deadlines that exclude weekends and holidays, use the Business Days Calculator. To find the hours between two clock times, use the Elapsed Time Calculator, and to convert a meeting time between zones, use PST to CST.
Frequently asked questions
Yes — the calculation uses real calendar date arithmetic, so leap years are handled correctly without any extra steps.
Yes — switch the direction to "before," and the calculator finds the date that many days prior to your starting date.
The starting date counts as day 0 — adding 1 day to a date gives you the very next calendar day, which matches how most people naturally count "days from now."
It is Thursday, April 1, 2027. Counting from January 1, there are 30 more days in January, 28 in February 2027 and 31 in March, which reaches March 31 after 89 days; the 90th day is April 1. The calculator does this counting for any start date.
Yes. 2028 is divisible by 4 and is not a century year, so February 2028 has 29 days. Century years are leap years only when divisible by 400, which is why 2000 was a leap year and 2100 will not be.
Add one to the plain difference. From January 1 to January 31 is 30 days, but counting both January 1 and January 31 gives 31 days. Tick Include the end date and the calculator adds that day for you, along with the matching weeks and weekday totals.
No. The weekday figure counts Monday through Friday only and treats every one of them as a working day. Public, regional and company holidays are not removed, so subtract any holiday that falls on a weekday in your range, or use the Business Days Calculator, which removes holidays for you.
Choose the add option, enter the start date and 30 days, and read the result. Adding 30 days to January 1, 2027 gives January 31, 2027. Adding 30 days to January 31, 2027 gives March 2, 2027, because February is shorter.