This date calculator lets you calculate the difference between two dates or add and subtract days, weeks, or months to find a future or past date. It is useful for deadlines, age checks, event planning, and work schedules.
- Date difference: Enter two dates to see the exact difference in years, months, days, and weeks.
- Add or subtract: Add or subtract any number of days, weeks, or months from a starting date.
- Business and personal use: Plan projects, track age milestones, or calculate work schedules.
- Quick results: Get answers instantly with clear breakdowns for days, weeks, and months.
How to use: In Date Difference mode, select two calendar dates and get the full duration. In Add/Subtract mode, choose a start date and enter how many days, weeks, or months to adjust. The calculator will show your new date instantly.
Common searches: date difference calculator, add days to date calculator, subtract weeks from date, how many days between two dates.
Date Calculator
Find the difference between two dates, or add and subtract days, weeks, and months from a given date.
How the date calculator works
The date calculator uses simple date arithmetic to find either the difference between two dates or a new date after adding or subtracting time. It counts days, then converts them into weeks, months, and years for easy understanding.
Date difference explained
Date difference is calculated by subtracting one date from another. The total number of days is then broken down into years, months, and days. For example, the difference between January 1, 2024 and March 15, 2025 is 1 year, 2 months, and 14 days, or 439 days total.
Adding or subtracting days
Adding days means moving forward in the calendar, while subtracting days moves backwards. The calculator adjusts automatically for leap years, different month lengths, and year changes.
Worked examples
- Date difference: From July 1, 2024 to December 31, 2024 = 183 days or 26 weeks and 1 day.
- Add days: July 1, 2024 + 100 days = October 9, 2024.
- Subtract weeks: December 31, 2024 − 12 weeks = October 8, 2024.
- Add months: January 15, 2025 + 6 months = July 15, 2025.
Quick reference table
Here are some common date adjustments for planning purposes:
| Adjustment | Example Start Date | Resulting Date |
|---|---|---|
| +7 days | Jan 1, 2025 | Jan 8, 2025 |
| +30 days | Jan 1, 2025 | Jan 31, 2025 |
| +1 month | Jan 15, 2025 | Feb 15, 2025 |
| +6 months | Jan 15, 2025 | Jul 15, 2025 |
| +1 year | Jan 1, 2025 | Jan 1, 2026 |
Why use a date calculator?
Date calculators save time and reduce errors when working with schedules, deadlines, and timelines. They are widely used by students, project managers, accountants, HR teams, and anyone planning events or travel.
Limitations of date calculators
This calculator shows calendar-based differences and adjustments but does not include public holidays unless added manually. For business or legal use, always confirm with official calendars.
Date Calculator FAQs
The difference is found by subtracting one date from another. The calculator converts the total days into years, months, and weeks for clarity.
A normal year has 365 days, while a leap year has 366 days. The calculator automatically adjusts for leap years.
Yes. The calculator lets you add or subtract months, adjusting automatically for shorter and longer months.
The standard calculation includes all calendar days. Business days or holidays must be handled separately.
The date calculator is accurate for calendar math. However, official business or legal deadlines should always be checked against verified calendars.
The calculator instantly shows the new date after adding or subtracting days, weeks, or months, saving manual counting.
Yes. You can calculate differences or add/subtract days from any date, whether it is in the past or future.