A days between dates calculator tells you exactly how many days separate two calendar dates — including or excluding weekends — without any manual counting. Use it to calculate deadlines, measure project durations, plan travel, or find out what date falls a certain number of days in the future or past.
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How to Use the Days Between Dates Calculator
This free days between dates calculator handles three common date arithmetic tasks: finding the gap between two dates, adding a number of days to a date, and subtracting days from a date. All calculations happen instantly in your browser — no data leaves your device.
Mode 1: Days Between Two Dates
Select Days Between from the tab bar. Enter a start date and an end date using the date pickers, or click Today to fill in the current date automatically. Hit Calculate to see the results. The results panel shows four figures:
- Total Days — the raw calendar day count between the two dates.
- Business Days — weekdays only (Monday–Friday), with weekends excluded.
- Weeks + Days — the total broken down into complete weeks and remaining days.
- Approx. Months — an approximate month count based on 30.44 days per month.
Use the Include end date toggle if you want both the start and end days counted as full days of presence. By default only the start date is included (for example, January 1 to January 5 = 4 days). With the toggle on, the same range = 5 days — useful for event durations, hotel stays, and visa day counts.
Mode 2: Add Days to a Date
Switch to the Add Days tab. Enter a start date, type the number of days to add, then click Calculate. The tool shows the resulting date along with the day of the week. This mode is handy for working out project deadlines, subscription renewals, warranty expiry dates, and notice periods.
Mode 3: Subtract Days from a Date
The Subtract Days tab works identically to Add Days but goes backwards in time. Enter a reference date and a number of days to subtract — the result is the earlier date. Common uses include finding when a 30-day return window started, calculating a past deadline, or working backwards from a due date to set milestones.
Tips for Accurate Results
When counting days for legal or contractual purposes (visa stays, lease agreements, payment terms), always clarify whether the contract counts the start day, the end day, or both. Different jurisdictions have different conventions. This calculator defaults to excluding the end date but the toggle lets you match either convention in one click. For business day counts, note that public holidays are not excluded because they vary by country — you may need to subtract any holidays manually if your context requires it.
Frequently Asked Questions
Is this days between dates calculator free?
Yes, completely free. There is no signup, no account required, and no limit on how many calculations you can run. Everything happens in your browser — no data is sent to any server.
Does it count the end date as a full day?
By default the end date is excluded from the count, matching the most common convention (e.g., Jan 1 to Jan 3 = 2 days). You can toggle the 'Include end date' option to count both the start and end days, which gives you Jan 1 to Jan 3 = 3 days.
How are business days calculated?
Business days count only Monday through Friday. Saturdays and Sundays are skipped. Public holidays are not currently excluded because they vary by country — the business day count is a weekend-only filter that works worldwide.
Can I add or subtract days from a specific date?
Yes. Switch to the 'Add Days' or 'Subtract Days' tab, enter a start date and a number of days, and the calculator instantly shows the resulting date. This is useful for working out deadlines, delivery dates, trial expiry dates, and similar tasks.
How do I calculate the number of weeks between two dates?
Use the 'Days Between' mode and enter your two dates. The result panel shows total days broken down into complete weeks plus remaining days — for example, 45 days is shown as 6 weeks and 3 days.
What if I need to calculate months between two dates?
The result panel displays an approximate months figure alongside total days and weeks. The month count is calculated by dividing total days by 30.44 (the average days per month), so it is an approximation rather than a calendar-month count.
Is my data private?
Yes. All calculations run entirely in your browser with JavaScript. No dates or personal data are transmitted to any server. The tool works offline once the page has loaded.