Date Calculator
Calculate the duration between two dates or find a future/past date by adding days, weeks, months, or years. Free online calendar tool.
About Date Calculations
This Date Calculator helps you find future or past dates by adding days, weeks, months, or years. It also calculates the duration between any two calendar dates.
Common Uses
- Planning Events: "What date is 6 weeks from today?"
- Deadlines: "When is 90 days after my contract started?"
- Age Calculation: Determine exactly how many days old you are.
- Pregnancy: While we have a dedicated pregnancy calculator, this tool can add 280 days to your last period to estimate a due date manually.
Handling Leap Years
The calculator accounts for leap years (29 days in February) and varying month lengths (28, 30, 31 days). When adding months, if the target day doesn't exist (e.g., adding 1 month to Jan 31st), standard behavior usually lands on the last day of the next month (Feb 28th/29th) or rolls over to March 1st depending on the specific library logic. This tool follows standard JavaScript date rollover rules.
? Frequently Asked Questions
The 'Date Difference' mode calculates the duration *between* the dates. If you want to include the last day (inclusive count), simply add 1 to the 'Total Days' result.
When calculating the difference, 'months' refers to full calendar months passed. The remaining days are then counted.
Yes, use the 'Add / Subtract' tab and select 'Subtract' to go back in time from a starting date.