📅 Days Between Dates
Difference in days, weeks, months and years
➕ Add / Subtract From Date
Days, weeks, months or years
Free Date Calculator — Days Between Dates, Add or Subtract Time
Quickly calculate the number of days, weeks, months and years between two dates, or add and subtract days, weeks, months or years from any date. Exclude weekends or holidays to get accurate working-day counts, which makes planning events, deadlines and schedules simple and fast.
Quick answer: there are 364 days between January 1 and December 31 in a regular year, and 365 in a leap year. For any other pair of dates, use the calculator above. The page has two tools: one for the difference between two dates, and one for adding or subtracting time from a date.
How to Calculate the Days Between Two Dates
Subtract the earlier date from the later one. From March 3 to March 10 is 7 days. When the dates fall in different months, count the days left in the first month, add the full months in between and the days in the last month. Leap years add an extra day in February, which is easy to forget when counting by hand.
Two numbers are shown because people count in two ways. Total Days is the plain difference, so January 1 to January 2 is 1 day. Days Counted includes both the start and the end date, which is how working days are normally counted, and it leaves out any weekends or holidays you choose to exclude.
| Days | Months |
|---|---|
| 31 days | January, March, May, July, August, October, December |
| 30 days | April, June, September, November |
| 28 or 29 days | February (29 in a leap year) |
Working Days Between Dates: Excluding Weekends and Holidays
Tick Exclude Weekends and every Saturday and Sunday in the range is left out. To skip holidays too, type them in YYYY-MM-DD format separated by commas, for example 2026-12-25, 2027-01-01. A project that runs from Monday, January 5 to Friday, January 30, 2026 spans 26 calendar days when both dates are counted. Six of those are weekend days, which leaves 20 working days. For an even simpler count, try the business days calculator.
Adding and Subtracting Days, Weeks, Months and Years
A week is always 7 days, but months and years follow the calendar. The calculator keeps the same day number when it can, and when the target month is shorter it uses the last day of that month. January 31 plus one month is February 28, or February 29 in a leap year. For example, 90 days after April 15, 2026 is July 14, 2026. Use Subtract to go back in time, such as finding the date 30 days before a deadline.
Leap Years and Week Numbers
A year is a leap year if it divides by 4, except for century years, which must divide by 400. That makes 2024 and 2000 leap years, while 1900 and 2100 are not. The week number follows ISO 8601: weeks run from Monday to Sunday, and week 1 is the week with the first Thursday of the year. Results use the full month name, such as March 4, 2026, so they read the same in every country.
What Can You Use a Date Calculator For?
Common uses include project deadlines, contract notice periods of 30, 60 or 90 days, invoice due dates, delivery and travel planning, event countdowns and study schedules. To find someone's exact age in years, months and days, use the age calculator, and for time rather than dates try the time calculator.
How to Use This Date Calculator
Pick a start and an end date
Use the date picker on your device, or type the dates. If they are reversed, they are swapped for you.
Choose what to exclude
Tick Exclude Weekends, and add any holidays in YYYY-MM-DD format.
Press "Calculate Days"
See total days, weeks, a breakdown in years, months and days, and the days counted.
Pick a base date and an amount
Choose days, weeks, months or years as the unit.
Press Add or Subtract
The new date appears with its weekday, week number and leap year status.