Free calculator · No account needed
Date Calculator:
Days Between Dates
Count days, weeks and calendar time between two dates, or add and subtract years, months, weeks and days. Plan a deadline or repeat an interval.
Choose your starting point
Your result
Choose your dates and amounts, then select Calculate date. Your result will appear here.
Calendar dates only. Time zones and daylight saving do not change the day count. Weekends and holidays are included.
How are days counted?
By default, the same date is zero days apart. Turn on “Include the end date” to count both dates. Earlier end dates show how many days you move back.
What about leap years?
February 29 is included in leap years. Adding a year to February 29 moves to February 28 when the next year has no leap day.
What happens at month-end?
Adding one month to January 31 gives the last day of February. Repeat calculations carry this adjusted date into the next step. Results use Moment.js and the Gregorian calendar.
Date calculation examples
How many days from January 1 to January 31?
The difference is 30 days. Select “Include the end date” to count both dates and get 31 days. Weekends and holidays are included.
What date is one month after January 31?
It lands on the last day of February: February 28 in a common year or February 29 in a leap year. Repeating the calculation starts from that adjusted date.
The calculator uses calendar dates in the Gregorian calendar. It does not count working days, public holidays or time-zone hours.
Example: count a deadline interval
October 1 to October 8 is seven days apart. With Include the end date enabled, the count becomes eight days. These are calendar days, so weekends and public holidays are included. For a legal or contractual deadline, check the required counting rule separately.
How do I add time instead?
Choose the add/subtract mode, enter a starting date and a nonnegative amount for years, months, weeks or days, then calculate. Units are applied in that order. Each repeat begins from the previous adjusted date, so month-end adjustments can carry forward.