Count the days since (or until) any date, find the days between two dates, or add/subtract days, weeks, months and years from a date.
How to use this tool
Choose “Days between” for the gap between two dates, “Add / subtract” to move a date forward or back, or “Since / until” to compare a date with today.
Type or pick the dates from the calendar. For Add / subtract, also enter a duration in days, weeks, months or years.
Results update as you type: exclusive days, the inclusive count, business days, weeks and an approximate month count.
Copy the result for a deadline, a countdown, a project plan or a booking — no sign-up needed.
Formula & worked example
From 1 January 2026 to 21 October 2026 is 293 days (294 days inclusive). Adding 90 days to 21 October 2026 gives 19 January 2027, a Monday — which is why “90 days from today” is a popular way to work out a 3-month deadline.
Limitations — read this before you rely on it
Counts use the Gregorian calendar and whole days only — times of day are not included. “Approx. months” divides by 30.4375 (the average month length), so it is an estimate, not a calendar-month count. Business days exclude Saturdays and Sundays but do not exclude public holidays, which vary by country.
Frequently asked questions
A date calculator works out distances between dates or moves a date forward or back. This one covers days between dates, adding or subtracting a duration, and days since or until a date.
A days calculator counts whole days between two dates. By default the start date is not counted (exclusive count); the inclusive count, which counts both dates, is shown alongside it so you can use whichever you need.
Enter the earlier date and the later date in “Days between” mode. You get the day count, the inclusive count, business days, weeks and an approximate month count — in either date order.
Use “Add / subtract” mode with today as the starting date and a duration of 90 days. From 21 October 2026, 90 days later is 19 January 2027. The answer always depends on today's date, so it is recalculated live.
Business days are Monday-to-Friday days after the start date up to and including the end date. Weekends are skipped, but public holidays are not removed, since they differ by country.