Add or subtract days, months, or years to/from a date
How date arithmetic works
Date addition and subtraction is more complex than it looks because months have different lengths and leap years add an extra day every 4 years. Adding days: Straightforward — add the number of days directly to the date, rolling over months and years as needed. Adding 30 days to January 15 gives February 14. Adding months: This is where it gets tricky. Adding 1 month to January 31 should give February 28 (or 29 in a leap year) — not March 3. Proper date calculators handle this 'end of month' clipping automatically. Adding years: Adding 1 year to February 29 (leap day) gives February 28 the following non-leap year. Edge cases like this are handled automatically by this calculator. Common uses: Contract expiry dates (6 months from signing), subscription renewal (1 year from today), payment due dates (30/60/90 days), project milestones, warranty end dates, trial period end dates, and legal deadlines.
About date calculations
Select start date, choose 'Add', enter 90 days, and calculate.
Other useful tools related to date calculations
How to Use? Select start date, choose add or subtract, enter value and unit. Result is calculated automatically.
Calculate 90 days from now, 30 days ago
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Contract terms and due dates
About date calculations
Select start date, choose 'Add', enter 90 days, and calculate.