CalcJoy

Date Calculator

Pick a date, choose to add or subtract, and we'll tell you the resulting date and weekday.

Inputs

Result

Result date
Saturday, June 13, 2026
2026-06-13 · Saturday

Visual breakdown

Start
2026-05-14
Change
+30 days
Result
2026-06-13
Weekday
Saturday

Formula

Days/weeks shift the timestamp by 86,400 s × N. Months/years use real calendar arithmetic — month-end dates are clamped to the next month's last day.

Example

1 Jan 2026 + 30 days = 31 Jan 2026 (Saturday).

Frequently asked

What about month-end edge cases?

Adding 1 month to 31 Jan rolls forward, so February's last day is used (28 or 29). This matches most calendar apps.

Are leap years handled?

Yes — adding years to 29 Feb in a leap year lands on 28 Feb in non-leap years.

Can I subtract a date instead?

For days between two dates, use the Date Difference Calculator.

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