How to Calculate Date
What is Date?
A date calculator adds or subtracts days, weeks, months, or years from a date to find a resulting date. Useful for project deadlines, contract expiration dates, subscription renewals, legal deadlines, and age milestones.
Step-by-Step Guide
- 1Adding days: count forward from the start date
- 2Adding months: add to the month number, handle year rollovers and month-end edge cases
- 3Leap years: divisible by 4 (except centuries unless divisible by 400)
- 4Business day calculations exclude weekends (and optionally holidays)
Worked Examples
Input
Jan 15, 2024 + 90 days
Result
April 14, 2024
Common "net 90" payment term
Input
March 31 + 1 month
Result
April 30
April has 30 days, so end-of-month
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