Date & Time

Date Add/Subtract Calculator

Free date calculator to find a future or past date by adding or subtracting any combination of days, weeks, months, and years.

Calculate Future and Past Dates

Need to find a deadline 90 days from now? Or what date was 6 months ago? Our date calculator adds or subtracts any combination of days, weeks, months, and years from any starting date.

Date Arithmetic

Date calculations are complex because months have different lengths, years can be leap years, and adding months doesn't always result in a valid date (like adding 1 month to January 31). Our calculator handles all these edge cases correctly.

Example

March 15 + 90 days = June 13

Why Use This Calculator?

Accuracy

Automatically handles months of different lengths and leap years.

Flexibility

Add or subtract in days, weeks, months, or years.

Planning

Perfect for calculating deadlines and timelines.

How to Calculate

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Applications

Deadlines

Calculate when projects or payments are due.

Contracts

Determine contract expiration dates.

Events

Plan events a certain time in the future.

Medications

Calculate when to renew prescriptions.

Frequently Asked Questions

If the resulting month doesn't have that day, it uses the last day of the month. For example: January 31 + 1 month = February 28 (or 29 in a leap year).