Calculate days between two dates, count business working days, or add and subtract days from any calendar date.
The Date Calculator helps you measure the exact duration between two calendar dates or calculate future and past target dates. You can count total days, weeks, months, or exclude weekends to count business working days.
All calendar math runs locally inside your browser. Your event dates, project schedules, and contract deadlines are never transmitted to external servers.
Managers calculate working day intervals between milestone deliverables and client review dates.
Attorneys calculate exact 30-day or 60-day statutory response windows from formal notice delivery dates.
Planners count exact days remaining until weddings, conferences, or product releases.
Select "Difference Between Dates" or "Add/Subtract Days".
Choose your start date and end date from the calendar picker.
See the exact number of days, weeks, and working business days.
Dual modes: Calculate days between dates or add/subtract time from a date
Business days calculator option excluding weekend days
Accurate leap year calculations across past and future decades
100% private in-browser calculation with offline capability
Find the deadline 45 calendar days after October 1.
Accounts for the 31 days in October to calculate the precise calendar deadline.
Solution: Use the "Include End Date" checkbox if your calculation requires counting both the start and end days.
MWT Labs tools are built using modern web primitives—including WebAssembly, Web Workers, and native HTML5 Canvas / Cryptography APIs. When you process images, parse PDF documents, format JSON payloads, or calculate financial schedules, execution happens strictly within your local browser memory sandbox.
You can calculate the exact duration between two dates (in days, weeks, and months), or add/subtract any number of days, weeks, or months to or from a starting date to find a future or past date.
Yes. The calculator incorporates full Gregorian calendar leap year rules, accurately accounting for February 29th across all past and future leap years.
Yes. You can toggle the business day option to count only Monday through Friday working days between two selected dates.
Yes. You can enter a contract signing date or project kickoff date and add the required number of days (e.g., 30, 60, or 90 days) to find the exact legal or delivery deadline.
Yes. All calendar math executes entirely client-side in your web browser. No network connectivity is required once the page is loaded.