Time calculator
Date Calculator
Add or subtract days, weeks, months, and years from a start date.
Quick answer
How do you add days to a date?
Start from the date and count forward (or backward) the number of days, rolling over months and years as needed. For example, 90 days after January 1, 2026 is April 1, 2026.
⚡ Answer updates as you type · Enter = calculate · Esc = reset
The Date Calculator adds or subtracts days, weeks, months, and years from a start date to find a new date.
About this Date Calculator
Add or subtract days, weeks, months, or years from any starting date. Useful for due dates, project deadlines, contract renewals, and anniversaries.
What you'll need
- • Start date
- • Amount
- • Unit (days, weeks, months, years)
- • Add or subtract
How it works
- 1. Pick a start date.
- 2. Choose to add or subtract.
- 3. Enter an amount and unit.
- 4. Read the resulting date and the day of the week.
Worked example
Adding 90 days to May 7, 2026 gives August 5, 2026.
Related searches
Date Calculator FAQ
What is the Date Calculator?
The Date Calculator is a free online tool that helps you add or subtract days, weeks, months, and years from a start date.
How do I use the Date Calculator?
Open the Date Calculator, enter the requested values, and review the instant estimate on the page.
Is the Date Calculator free?
Yes. The Date Calculator is free to use on Fast Online Calculator and does not require an account.
Does the calculator handle leap years?
Yes, leap years and end-of-month edge cases are handled automatically.
Can I calculate the difference between two dates?
Use the Days Between Dates calculator for that.
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