Date Calculator is now live on Tools.Town — a tool that lets you add or subtract any combination of days, weeks, months, and years from a starting date to find the resulting date, without counting squares on a calendar.
Set a contract start date, add 90 days, and know the exact deadline. Calculate an invoice due date, a warranty expiry, a subscription renewal — all in seconds.
What Does It Do?
Add Duration
Add any number of days, weeks, months, or years to a start date to find the future date.
Subtract Duration
Go backwards from a date to find when something started — useful for calculating age, lead time, or history.
Date Details
See the result date's day of week, week number, and formatted output in multiple styles.
Handles edge cases like month-end roll-overs and leap years automatically — no manual adjustment needed.
How It Works
Pick a start date
Select your start date using the date picker or type it directly.
Set the duration
Enter how many days, weeks, months, and/or years to add or subtract.
Get the result
The result date appears immediately with the day of the week and week number.
Why We Built It
Mental date math breaks down fast once you mix units. How many days are in 3 months and 2 weeks? It depends on which months. Date Calculator handles the calendar arithmetic correctly, accounting for varying month lengths and leap years, so you get reliable answers every time.
Try It Now
Date Calculator
Add or subtract days, weeks, months, and years from any date. Find deadlines, expiry dates, and past dates instantly.
Also useful: Date Difference to find how many days between two specific dates, and Business Days Calculator to skip weekends.
Related Posts
Frequently Asked Questions
Can I add and subtract different units at once?
Does it handle month-end edge cases?
What date format does it use?
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