Date Calculator

Find how many days are between two dates — also as weeks and days, months and days, and working days — or add and subtract days, weeks, months and years to get a new date. Handy for exam and holiday countdowns, project deadlines, notice periods and fee due dates. Leap years and month ends are handled for you.

Start date

End date

Include the end date (count both days)

Working days — weekend is

How to use the date calculator

Choose "Days between dates" or "Add / subtract".
For days between: pick the start and end dates, and tick "include the end date" if both days should count (for example, the days of a trip).
Choose a weekend rule to get working days (Saturday–Sunday off or only Sunday off).
For add / subtract: pick a date, enter years, months, weeks and days, and choose add or subtract.

Formulas

Days between	`End date − start date (+ 1 if the end date is included)`
Weeks and days	`Days ÷ 7 → quotient = weeks, remainder = days`
Leap year	`Divisible by 4, except century years not divisible by 400` 2024 and 2000 are leap years; 1900 and 2100 are not.
Add months	`Same day number in the new month; if it does not exist, the month’s last day` 31 Jan + 1 month = 28 Feb (29 Feb in a leap year).

Solved examples

Example 1: How many days are there from 1 Jan 2024 to 31 Dec 2024?

End − start = 365 days
2024 is a leap year, so including both dates gives 366

Answer: 365 days between (366 including the end date)

Example 2: What date is 100 days after 13 October 2026?

13 Oct + 18 days = 31 Oct
+ 30 (Nov) + 31 (Dec) = 79 days → 31 Dec
+ 21 days → 21 Jan 2027

Answer: 21 January 2027 (Thursday)

Example 3: How many working days (Mon–Fri) are there from Monday 12 Oct 2026 to Monday 26 Oct 2026?

14 days = 2 full weeks
2 × 5 working days = 10

Answer: 10 working days

Should the end date be counted?

For "how many days until" questions — days until an exam, days left in a notice period — do not include the end date: from 1 March to 3 March is 2 days. For "how many days did it last" questions — a school trip from 1 to 3 March, a 3-day leave — include both dates, giving 3 days. Tick the box to switch.

Why the result never shifts by a day

Many online date tools use the local clock, so a daylight-saving change in some countries can make a gap look one day short. This calculator works only with calendar dates in UTC, so 1 March to 1 April is always 31 days, wherever you are. Public holidays differ by state and are not removed from working days.

🎯 Calendar questions in reasoning

Day-and-date questions are a regular part of the reasoning section in:

SSC CGL & CHSL
IBPS & SBI PO / Clerk
RRB NTPC
Bank exam reasoning (calendar questions)

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Frequently asked questions

How do I calculate the number of days between two dates?

Subtract the start date from the end date. Count the days left in the start month, add the days of each full month in between, then add the days of the end month. The calculator does this instantly and shows the working.

How many days are there in a leap year?

366. February has 29 days in a leap year. A year is a leap year if it is divisible by 4, except century years, which must be divisible by 400 (2000 was a leap year, 1900 was not).

What is 31 January plus one month?

There is no 31 February, so the result is the last day of February: 28 February, or 29 February in a leap year.

Does the working days count remove public holidays?

No. It removes weekends only (Saturday and Sunday, or only Sunday). Subtract holidays from your state or office calendar yourself.

How many weeks are in 100 days?

100 ÷ 7 = 14 weeks and 2 days.

How many days are left until my exam?

Put today as the start date and the exam date as the end date. For a live countdown with hours and minutes, use the Exam Countdown tool.