Date Calculator: Add or Subtract Days
Find the exact future or past date by adding or subtracting days, weeks, months, or working business days from any date.
30 days after start date is:
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How to Add or Subtract Days from Any Date
Using our Date Calculator, you can instantly determine a future or past date by offsetting calendar days, business days, weeks, months, or full years from any reference start date. Whether you are tracking visa 90/180 rule limits, managing legal filing deadlines, calculating pregnancy due dates, or planning project milestones, this tool computes exact calendar duration without requiring manual calendar flipping.
Step-by-Step Instructions
- Select your Start Date: Pick any starting point on the calendar. By default, it uses today's date.
- Choose Operation: Toggle between Add Time (+) for future dates or Subtract Time (-) for past dates.
- Input Duration: Enter the number of units and select Days, Weeks, Months, or Years from the dropdown menu.
- Toggle Business Days (Optional): Check "Count business days only" to automatically bypass Saturdays and Sundays.
- Read Target Date: Instantly view the formatted target date, weekday name, day-of-year index, and ISO week number.
Worked Examples for Common Intervals
| Preset Interval | Common Use Case | Calculation Method |
|---|---|---|
| +30 Days | Invoice payment terms (Net 30), product return policy | Adds 30 consecutive calendar days |
| +60 Days | Tenant notice periods, contract renewal warnings | Adds 60 consecutive calendar days |
| +90 Days | Schengen tourist visa stays, corporate probation reviews | Adds 90 consecutive calendar days |
| +180 Days | Semi-annual financial reporting, passport validity rules | Adds 180 consecutive calendar days |
| +280 Days (40 Weeks) | Obstetric pregnancy estimated due date (EDD) | Adds 280 calendar days from last menstrual period |
Calendar Days vs. Working Business Days
Standard calendar calculations include every day of the week (Monday through Sunday, plus leap days). When measuring project deadlines or banking settlements, selecting "Count business days only" iterates exclusively through Mondays, Tuesdays, Wednesdays, Thursdays, and Fridays. For instance, adding 10 business days to a Monday lands 14 calendar days later on the second Monday, successfully skipping 4 weekend days.
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Frequently Asked Questions
What date is 90 days from today? ▼
Click the "+90 Days" quick preset above to instantly see the exact date, weekday, and week number 90 days into the future starting from today.
How does leap year affect adding a full year (365 days)? ▼
A standard calendar year has 365 days, whereas leap years contain 366 days (including February 29th). If your interval crosses a leap day, adding 365 calendar days will fall on the day before the same date next year, while adding "1 Year" lands on the identical calendar date.
Can I add working business days only? ▼
Yes. Toggle the "Count business days only" checkbox. The calculator will advance day-by-day and exclude all Saturdays and Sundays automatically.