Days Calculator: Count Days Between Dates & Add Days

Count days between dates, add days to find deadlines, or calculate date differences. Free, instant, handles leap years.

Count days between two dates, add days to find a future date, or calculate deadlines instantly.

Free days calculator — count days between two dates, add or subtract days, weeks, or months, and calculate deadlines instantly. Handles leap years and varying month lengths. Useful for planning, billing cycles, contracts, and everyday calendar math.

How this page is maintained

  • Steps and copy are checked against the current tool behavior.
  • Browser limits, file-size constraints, or compatibility gaps are documented when relevant.
  • Unless a page explicitly says otherwise, files and text stay in the browser during processing.

Your Free Days Calculator & Date Counter

Need to count days between two dates, figure out what date is 90 days from now, or calculate a deadline? This date calculator handles all common calendar math instantly. Enter your dates, get your answer—no sign-up, no server processing.

Eliminating Mental Calendar Math

Manually calculating the exact number of days between February 14th and October 31st across different years is highly prone to human error, especially when factoring in leap years or irregular month lengths. Our Date Calculator offloads this arithmetic to a mathematically flawless browser engine.

Two Modes: Days Between & Add Days

This tool is built for two distinct workflows:

  1. Date Counter (Days Between): Input a start and end date to instantly see the total days, weeks breakdown, and full year/month/day decomposition between them. Perfect for project timelines, contract durations, event countdowns, or answering "how many days until..." questions.
  2. Day Calculator (Add/Subtract): Enter a start date and a number of days, weeks, or months to project forward or backward. Ideal for deadline planning ("What date is 60 days from today?"), billing cycles, due dates, and notice periods.

Common Questions This Calculator Answers

  • How many days between two dates?
  • What date is 30 / 60 / 90 days from today?
  • How many days until Christmas, a wedding, or a deadline?
  • When does a 14-day return window or 60-day notice period end?
  • How many days have I been alive?

The Leap Year Guarantee

Because this tool natively leverages your browser's underlying Date object API rather than a hacky server-side script, it inherently understands the complete Gregorian calendar. It flawlessly accounts for February 29th leap years, 30-day months, and varying month lengths without error.

Key features

  • Date Difference: Calculate the exact number of days, or a breakdown of years, months, and days between two dates.
  • Add or Subtract Time: Find out what date it will be in 30 days, or what date it was 5 weeks ago.

Frequently asked questions

Does this include the end date in the count?

The "days between" calculation typically counts the duration, so it is effectively exclusive of the start date and inclusive of the end date (or vice versa). It measures the time span.

Does it handle leap years?

Yes. The calculator uses the browser's native Date object, which perfectly handles leap years (February 29th) and varying month lengths.

Can I calculate business days only?

Currently, this tool calculates total calendar days. We are working on a "Business Days" mode that excludes weekends and public holidays.

How far back can I calculate?

You can calculate dates from year 100 AD up to year 9999. It is perfect for historical research or long-term planning.

Related guides

  • What Date Is 90 Days From Today? Free Deadline Calculator for Notice Periods and Contracts (2026)

    TL;DR If your starting date is April 11, 2026, then 90 days later is July 10, 2026. Instead of counting month by month every time, use the Days Calculator to add 30, 45, 60, or 90 days to any date instantly. If you are searching for what date is 90 days from today, you usually do not need calendar theory. You need the answer fast because a deadline depends on it. That deadline might be: a con…

  • Days Calculator: Count Days Between Dates, Add Days & Plan Deadlines (2026)

    How many days between two dates? What date is 90 days from now? When does a 60day notice period end? TL;DR — Use the Days Calculator to count days between any two dates or find a future/past date by adding days, weeks, or months. Instant, free, handles leap years automatically. Open the calculator → Whether you call it a days calculator, date counter, datetodate calculator, or calendar calcula…

Browse the full tool directory