Date Calculator
Find the number of days between two dates, or add/subtract days.
How to use the date calculator
- Choose 'Difference between dates' or 'Add/subtract days'.
- Enter the required dates or number of days.
- The result updates automatically.
Calculate the exact number of days, weeks, and months between two dates, or add or subtract a number of days from a starting date. Comes in handy for planning, deadlines, and scheduling.
Common date calculations
Counting the days between two dates is useful for project deadlines, notice periods, rental terms, pregnancy and due dates, trips, and how long until an event. The calculator handles different month lengths and leap years for you.
Adding or subtracting days answers questions like 'what date is 90 days from today?' for payment terms, warranty periods, visa stays, or return windows. For example, 30 days after January 15 is February 14.
Frequently asked questions
Does the calculation include both start and end dates?
The day difference is the number of full days between the two dates (the end date is not counted as an extra day).
Can I subtract days from a date?
Yes, in 'Add/subtract days' mode you can enter a negative number of days to go backward from a date.
How many days are in a year?
365 days, or 366 in a leap year. Leap years happen every 4 years, except for century years not divisible by 400.
What date is 100 days from today?
Choose 'Add/subtract days', keep today as the start date, and enter 100 to see the exact date.