Date Calculator
Add or subtract days from a date and get the result date.
Runs in your browser. Nothing is uploaded — your input is processed on this device and discarded when you close the tab.
Date Calculator
How to use this tool
- Pick a start date.
- Choose Add days or Subtract days and enter the number of days.
- Press Generate to see the result date and its weekday.
Worked example
Starting from 15 January 2026 and adding 30 days gives 14 February 2026, a Saturday.
What this tool does not do / Limits
This tool counts calendar days only, using the UTC calendar date so the result does not shift with time zones. It does not skip weekends or public holidays and does not handle times of day.
Frequently asked questions
Does adding 30 days mean one month?
No, it means 30 calendar days. Adding one calendar month can land on a different date, because months have 28 to 31 days.
Why use the UTC date?
Using the UTC calendar date keeps the result the same no matter where the browser is, instead of shifting near midnight in some time zones.
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