Free Date Calculator
Two date tools in one: count the days between any two dates, or jump forward and backward from a date by any number of days.
Days between two dates
Add or subtract days
How to use the date calculator
- Days between: pick a start and end date to see how many days apart they are.
- Add/subtract: pick a starting date, choose add or subtract, and enter the number of days.
- Results land on the correct weekday automatically — month and year boundaries handled.
Date math tips
Counting days between dates is one of those things that looks easy until month lengths, leap years, and year boundaries get involved — which is exactly why a calculator beats mental math here. One convention to know: this tool counts the difference between the two dates, not including both endpoints. So Monday to Tuesday is 1 day, and a "7-day trip" starting Monday lands on the following Monday. That matches how most deadline, rental, and subscription math works. Adding days is equally handy: "90 days from today" for payment terms, "add 280 days" for a rough due date, or "subtract 6 weeks" to back-plan a launch. The resulting date always shows the weekday, so you can spot at a glance whether your deadline lands on a weekend. For business-day math (skipping weekends and holidays), you would need a workday calendar — but for raw day counts across any span, this is all you need.
Frequently asked questions
Are both the start and end dates counted?
No — this shows the difference between the dates. Monday to Tuesday is 1 day. If you need inclusive counting, add 1 to the result.
Does it handle leap years?
Yes. February 29th is included automatically whenever it falls inside your range, using the real Gregorian calendar.
Can I count business days only?
Not here — this counts calendar days. For business days, subtract roughly two days per full week as an estimate, or use a dedicated workday calculator.
What date format should I enter?
Use your browser's date picker, which handles the format for you. The math works the same regardless of locale.