Date calculator: days between dates & add days to a date

This free date calculator does two jobs in one. Switch the mode at the top to either find the number of days between two dates, or add (or subtract) days from a date to see exactly which date you land on — and what day of the week it falls on. Everything updates instantly in your browser.

Mode 1: days between two dates

Pick a start and end date to get the total days, the same span in weeks, a years/months/days breakdown, and the number of working days (Monday to Friday). This is handy for notice periods, interest and late-fee windows, exam countdowns and project planning.

Mode 2: add or subtract days from a date

Choose "Add / subtract days", enter a start date and a number of days, and the tool tells you the resulting date. For example, "from today, after 90 days, which date comes?" — just enter today and 90. To go backwards in time, put a minus sign before the number (for example −30 for 30 days earlier). This is perfect for finding due dates, return dates, deadline dates and "X days from now" questions.

Common uses

• Due dates: a return due "within 30 days" — add 30 to the start date.
• Notice and probation: find the exact end date of a 90-day period.
• Refunds and warranties: "valid for 180 days" — see when it expires.
• Planning: count days to an exam, event or milestone.

How the calculation works

For the difference, the tool counts the exact number of days between the two dates, correctly handling different month lengths and leap years. For adding days, it moves the calendar forward (or backward) by the number you enter and reports the new date and weekday. Working-day counts exclude Saturdays and Sundays only — not public holidays, which vary by state.

Frequently asked questions

How do I find what date it is after a number of days?

Switch to "Add / subtract days", enter the start date and the number of days, and the resulting date is shown with its weekday.

Can I subtract days to find an earlier date?

Yes — put a minus sign before the number, for example −45 for 45 days earlier.

How many days are between two dates?

Use the "Days between two dates" mode; it shows the total plus weeks and a years/months/days breakdown.

Does it count working days?

Yes, in difference mode it shows days excluding Saturdays and Sundays. It does not remove public holidays.

Does it handle leap years?

Yes, all counts are exact, including 29 February.

Which day of the week will the date fall on?

The add/subtract mode shows the weekday of the resulting date.

ComplyKraft provides free utilities; this tool works entirely in your browser. Working-day counts exclude weekends only, not public holidays.