Date Calculator — Days Between Dates, Add & Subtract Days, Business Days
Find the days between two dates, add or subtract days from a date, calculate working days and business days, determine a future date from today, and discover what day of the week any date falls on — all in one free online date calculator.
How to Use the Date Calculator — 3 Simple Steps
Pick from Add/Subtract Date, Date Difference, Business Days, or Day of Week using the tabs at the top of the calculator.
Use the date picker fields to set your start date, end date, or the specific date you want to evaluate. Quick-option buttons make common spans one click away.
Click the calculate button and see your result immediately — total days, weeks, months, business days, or the resulting date, all calculated with leap-year accuracy.
Date Calculator — Fast, Free & Accurate
Whether you need to know how many days are left until a deadline, what date falls 90 days from today, or how many working days stand between a project kick-off and its delivery, manual counting on a calendar is slow and error-prone. Our date calculator online handles all of that in under a second, accounting correctly for varying month lengths, leap years, and the Monday-to-Friday rhythm of working weeks.
The tool covers four distinct use cases on a single page. The Add/Subtract Date mode lets you combine years, months, weeks, and days into one operation — so you can calculate, for example, what date falls 1 year, 3 months, and 12 days from any starting point. The Date Difference mode gives you the gap between two dates expressed as total days, total weeks and remaining days, and a precise years-months-days breakdown. The Business Days Calculator counts only weekdays — no weekends — which is exactly what contract deadlines, payroll cycles, SLA commitments, and shipping estimates require. The Day of Week mode tells you, at a glance, whether any calendar date is a Monday, a Saturday, or anything in between.
Key Features
| Feature | Detail |
|---|---|
| Days between two dates | Exact calendar-day count with full year/month/day and week breakdown |
| Add days to a date | Combine years, months, weeks, and days in one calculation |
| Business days calculator | Weekday-only count (Mon–Fri), weekend exclusion toggle |
| Future date from today | Quick-option buttons for +1 day, +1 week, +30 days, +90 days |
| Calculate weeks from date | Shows weeks and remaining days for any date range |
| Leap year handling | February 29 included automatically in all calculations |
| Day of week finder | Returns weekday name plus day-of-year and week-of-year info |
| Year to date calculator | Enter Jan 1 and today to find elapsed days, weeks, and months |
When Do People Use This Tool?
- Project planning — Calculate how many working days remain before a milestone, or find the exact delivery date after a set number of business days.
- Legal and financial deadlines — Contract periods, notice windows, and payment terms are often expressed in calendar days or business days; this tool resolves both.
- Event countdowns — Find how many days until a birthday, wedding, holiday, or exam date to keep planning on track.
- HR and payroll — Count working days between pay periods, probation end dates, or contract start dates with the business days calculator.
- Medical tracking — Determine a date 28, 60, or 90 days from a prescription start, follow-up appointment, or treatment cycle.
- Education — Count the weeks remaining in a school term or calculate an assignment deadline from a given handout date.
Why Browser-Based Calculation Matters
Every calculation on this page runs entirely inside your browser using standard JavaScript date arithmetic. No date, input value, or query is sent to any server. There is nothing to download, no account to create, and no limit on how many calculations you run. Results appear the instant you click the button, making this a genuinely instant dates calculator online for daily use — whether you are on a laptop, tablet, or phone.
Frequently Asked Questions
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