Find the exact number of days, weeks, months, and years between any two dates — or calculate a future/past date by adding or subtracting time. Leap year accurate.
No formulas, no spreadsheets — just pick your dates and get precise results instantly.
Select "Days Between Dates" to measure a gap, or "Add / Subtract" to find a future or past date.
Type or pick your start and end dates using the date picker. Works for past, present, and future dates.
Toggle business days mode to exclude weekends, or enable "include end day" for full-period counting.
Instantly see a full breakdown — years, months, weeks, days — plus totals in days, hours, and weeks.
Date arithmetic uses the Gregorian calendar — the world standard — accounting for varying month lengths and leap years automatically.
Typical date ranges and what they equal in calendar days, weeks, and months.
| Duration | Calendar Days | Business Days (approx.) | Weeks | Months |
|---|---|---|---|---|
| 1 week | 7 days | 5 days | 1 week | 0.23 months |
| 2 weeks | 14 days | 10 days | 2 weeks | 0.46 months |
| 1 month | 28–31 days | ~21 days | ~4.3 weeks | 1 month |
| 30 days | 30 days | ~21 days | 4 wks 2d | ~1 month |
| 90 days | 90 days | ~64 days | 12 weeks 6d | ~3 months |
| 6 months | 181–184 days | ~130 days | ~26 weeks | 6 months |
| 1 year | 365 days | ~261 days | 52 weeks 1d | 12 months |
| 1 leap year | 366 days | ~262 days | 52 weeks 2d | 12 months |
Our date calculator is used daily by professionals, students, and individuals for a wide range of date calculations.
Calculate project durations, sprint lengths, and deadline countdowns with precise day counts.
Find your exact age in years, months, weeks, and days — far more precise than simply counting years.
Compute notice periods, contract durations, and filing deadlines in calendar or business days.
Track employee tenure, calculate probationary periods, and confirm payroll date windows accurately.
Count down to birthdays, anniversaries, weddings, or any special event in exact days and weeks.
Determine bond maturity dates, loan terms, invoice Net-30/60/90 windows, and interest accrual periods.
A date calculator is a free online tool that performs precise date arithmetic — measuring the exact number of days, weeks, months, or years between any two calendar dates, or computing a future or past date by adding and subtracting a chosen time offset. Instead of manually counting across months (which differ in length) or flipping through calendar pages, a date calculator delivers an instant, accurate answer in seconds.
Whether you need to know how many business days remain before a contract deadline, find the date exactly 90 days from today, or calculate someone's exact age in years, months, and days — this free date calculator handles it all in one click.
Enter the first date (start date) and the last date (end date) using the date picker. The calculator accepts any valid Gregorian calendar date — historical, current, or future — so you can measure everything from the days since a historical event to the time remaining until an upcoming deadline.
By default, the tool counts from the start date up to but not including the end date — the standard mathematical definition of a date difference. Enable "Include end day" to count both the first and the last date as full days. This is common in legal notice periods, rental agreements, and event duration calculations where both endpoint days are considered active days.
The result is displayed as a clear breakdown: X years, Y months, Z weeks, and W remaining days. Below that, you'll see total counts — total calendar days, total weeks, total months, and total hours — giving you the complete picture without any additional math.
Pro Tip: Enable Business Days mode to exclude Saturdays and Sundays from your count. This is essential for shipping estimates, court filing deadlines, invoice payment terms, and HR notice periods where only working days are counted.
The second mode answers a different question: "If I start on Date X and add Y days/weeks/months/years, what date do I land on?" This is useful for calculating return-by dates, subscription expiry dates, warranty periods, and project completion targets.
Enter your starting date, toggle between Add or Subtract, then enter any combination of years, months, weeks, and days. The calculator applies these offsets in the correct order — accounting for varying month lengths — and returns the precise resulting date along with the total number of days in the offset.
Example: You sign a contract on May 1, 2026 with a 6-month notice period. Adding 6 months gives November 1, 2026 — the correct result accounting for the actual lengths of May through October, rather than a naive 180-day estimate.
Calendar days count every single day on the calendar — Monday through Sunday, including public holidays. If a deadline is 7 calendar days from a Monday, it falls on the following Monday.
Business days (also called working days) count only Monday through Friday and exclude officially recognized public holidays. If a deadline is 7 business days from a Monday, it falls on the following Wednesday (skipping the two weekend days).
Use calendar days for: age calculations, event countdowns, subscription durations, loan terms stated as "Net 30/60/90," and any period where every day counts equally.
Use business days for: shipping and delivery estimates, court filing deadlines, employment notice periods, invoice payment terms in commercial contracts, and bank processing windows.
Every calculation this tool performs is grounded in the Gregorian calendar — the international civil standard used in over 140 countries and the basis for all modern legal, financial, and business date arithmetic.
The Gregorian system replaced the older Julian calendar in 1582, correcting a drift of approximately 11 minutes per year that had accumulated into a 10-day discrepancy over centuries. The key refinement was a more precise leap year rule: a year is a leap year if divisible by 4, except century years — which are only leap years if also divisible by 400. This keeps the calendar accurate to within one day every 3,030 years.
This matters because any date range spanning February 29th contains one extra day compared to the same range in a non-leap year. Our calculator accounts for this automatically, so you never need to check manually.
| New Year's Day | Jan 1, 2026 |
| MLK Jr. Day | Jan 19, 2026 |
| Presidents' Day | Feb 16, 2026 |
| Memorial Day | May 25, 2026 |
| Juneteenth | Jun 19, 2026 |
| Independence Day | Jul 4, 2026 |
| Labor Day | Sep 7, 2026 |
| Columbus Day | Oct 12, 2026 |
| Veterans Day | Nov 11, 2026 |
| Thanksgiving | Nov 26, 2026 |
| Christmas Day | Dec 25, 2026 |
| New Year's Day | Jan 1, 2027 |
| MLK Jr. Day | Jan 18, 2027 |
| Presidents' Day | Feb 15, 2027 |
| Memorial Day | May 31, 2027 |
| Juneteenth | Jun 19, 2027 |
| Independence Day | Jul 4, 2027 |
| Labor Day | Sep 6, 2027 |
| Columbus Day | Oct 11, 2027 |
| Veterans Day | Nov 11, 2027 |
| Thanksgiving | Nov 25, 2027 |
| Christmas Day | Dec 25, 2027 |
Everything you need to know about calculating date differences and date offsets.
Enter your start and end dates in the Days Between Dates calculator above and click Calculate. The tool instantly returns the difference expressed in years, months, weeks, and days — plus totals in calendar days, weeks, months, and hours. It accounts for leap years and varying month lengths automatically.
Switch to the Add / Subtract tab, enter today's date as the start date, set the Days field to 90, and click Calculate. The result shows the exact date 90 days from today — commonly used for return windows, warranty periods, and trial subscription end dates. Today is April 26, 2026, so 90 days from today is July 25, 2026.
Calendar days count every day of the week, including weekends and holidays. Business days count only Monday–Friday, excluding public holidays. As an example: 10 calendar days from a Monday is the Thursday of the following week, while 10 business days from a Monday is the Monday two weeks later. Enable Business Days mode in the calculator to get working-day counts.
Use the Days Between Dates tab. Enter your exact date of birth as the start date and today's date as the end date, then click Calculate. The result shows your precise age in years, months, weeks, and remaining days — far more accurate than simply subtracting birth years.
By default, the calculator counts from the start date up to but not including the end date — the standard mathematical difference. When you check "Include end day," both the first and last dates are counted as full days. This is used in rental periods, notice periods, and legal windows where both the start and end day are active days.
It depends on which three months are involved — months range from 28 to 31 days. Three months could be 89, 90, 91, or 92 days. The most accurate way is to use the Add to a Date calculator: enter your start date, add 3 months, and read the exact resulting date and total day count.
Yes — completely automatically. The calculator uses the Gregorian calendar rules, which means any date range that crosses February 29th in a leap year correctly includes that extra day in the count. You never need to check manually.
Yes — completely free, forever. No account required, no subscription, no hidden fees. SpeedCalculator.net is a free tool available to everyone with no usage limits.
Explore more free date and time calculators on SpeedCalculator.net.